Science Vocabulary Flashcards

Any change in the speed or direction of motion of an object.

A substance with a pH less than 7.0 that releases hydrogen ions in a water solution; for example, vinegar.

Rain that is highly acidic because of sulfur oxides, nitrogen oxides, and other air pollutants dissolved into it; can damage plant and animal life.

The energy needed to enable a chemical reaction to take place.

A process that helps an organism survive and function in its environment.

Being satisfactory; being sufficient for a job.

The changes that bring about the decline of an organism.

A large body of air that has the same moisture and temperature throughout.

The weight of the atmosphere.

Friction caused by air.

The tube that makes up the digestive canal.

A different form of a gene.

A radioactive particle made up of two protons and two neutrons bound tightly together.

A current in which the electrons flow first in one direction and then in the opposite direction.

Small air sacs in the lungs at the end of the bronchioles where oxygen passes in the blood and carbon dioxide is released from the blood.

The building blocks of proteins.

A procedure that is used to examine fetal cells to identify certain types of genetic disorders present in a fetus.

A covering that protects and nourishes a developing embryo.

The distance between the rest position and crest of a wave.

Substances produced by the body's immune system that fight diseases.

A protein on the surface of a pathogen.

A large artery that carries oxygen-rich blood from the heart to other parts of the body.

Taking information learned one set of circumstances and using it in another situation.

A blood vessel that carries blood away from the heart.

A method of reproduction in which an organism is produced from a single cell.

To determine the importance, adequacy, or significance of something.

A belief that something is true without checking its validity.

A small celestial body, sometimes called a minor planet, that revolves around the sun.

The study of all celestial bodies in the universe.

The layers of gases that surround the Earth.

The smallest particle of an element that can exist alone.

The sum of protons and neutrons in the nuclease of an atom.

The number of protons in the atom.

A compound in which energy is stored for later use in a cell.

One of the upper chambers of the heart (plural, atria)

The imaginary line running through Earth's center from the North Pole from the South Pole on which the planet rotates.

A segmented column of bones.

A one-celled organism that has DNA.

A chemical equation in which the same number of each type of atom appears on both sides.

A substance with a pH greater than 7.0 that releases hydroxide ions in a water solution; for example, milk of magnesia.

An organism's actions or reactions to its environment.

An electron emitted from the nuclease of a radioactive atom.

Anything that sways an experiment's results in a way that makes them inaccurate.

The idea that the universe began with an explosion of a dense, hot, compact mass under extreme pressure.

A method of reproduction in which a cell divides into two new cells.

Organic materials that naturally decompose.

A healthy variety of plant and animal species coexisting in an environment and making the environment more stable.

The principle that living things only come from living things.

An internal control of natural behavioral cycles.

A fundamental property that is common to all living organisms.

The study of all living things.

The total mass of the living organisms in a particular place.

The collapsed leftovers of a supernova.

A massive, hot star that uses up its hydrogen quickly, expands, and turs into a giant or supergiant

The temperature at which a liquid turns into a gas.

Force-carrying subatomic particles.

The study of plants.

The part of the human brain that controls automatic functions such as breathing and heartbeat.

The two tubes that lead from the trachea into each of the lungs.

Tubes branching off the bronchi in the lungs and ending in alveoli.

The part of a plant where the new growth takes place.

A measure of energy.

A coloring pattern that enables an animal to blend into their surroundings and not be seen by predators.

Very small blood vessels.

The main source of food energy.

A process that keeps the carbon on Earth in balance.

The continuous circulation of carbon and oxygen through the biosphere primarily through the processes of photosynthesis, respiration, and decomposition.

An animal that eats other animals.

The maximum population an ecosystem can support without losing resources.

A tough, flexible material that covers bones and joints.

A substance that provides a faster mechanism by which a reaction may take place.

Something that makes something else (an effect) happen.

Something that can make something else (a cause) happen results in another (an effect).

The smallest unit of life that can exist independently and that makes up all living organisms.

The process of division of a cell into new identical cells.

The soft, flexible covering that holds a cell together and separates it from other cells.

The process in which the cells of an organism develop in different shapes, structures, and functions.

A tough, flexible covering that surrounds the cell membrane of a plant cell.

The chemical process requiring oxygen by which living things convert food to energy.

The part of the brain , which controls movement, coordination, and balance; located below the cerebrum at the base of the skull.

The largest part of the human brain, which coordinates all higher functions such as perception, thinking, and conscious actually.

A reaction in which nuclei are split apart in a controlled way, resulting in a great quantity of nuclear energy.

A shorthand way of showing which elements are contained in a molecule.

A visual representation of data.

The process though which atoms are combined.

A change that produces a new substance.

A shorthand way of describing what happens in a chemical reaction.

The process in which two or more substances combine to form one or more substances.

Process that changes the composition of the rocks and occurs through chemical reactions.

The green substance in a plant cell that is used to capture light energy.

An organelle in a plant cell that contains chlorophyll.

The part of a cell's nucleus that contains genetic information.

A structure in a cell that contains DNA.

A biological clock that controls daily activity.

A form of faulty logic which a conclusion is supported by reasons that simply restate the conclusion.

the system, consisting of the heart, blood vessels, and the blood, that carries nutrients and oxygen to the body's tissues removes carbon dioxide and waste products.

Average weather conditions in a particular region over a long period of time.

The process of creating a genetically identical replica of an organism.

The theory that the universe at some future time will begin to contract and collapse into its original state as a solar nebula.

A solid fossil fuel.

A combination of three bases.

A number added to the reactants and the products to balance a chemical equation.

A classification of an organism that cannot control its own body temperature.

A mixture in which fine particles are spread out throughout a second substance; for example, foam.

When two or more moving objects run into one another.

A small object made of dust and frozen gas that orbits in a predictable path around the sun.

A relationship that benefits organism, while the other is neither harmed nor helped.

An individual in a species history to which all individuals in that species can be traced.

To identify how things are alike.

a type of metamorphosis that takes place in four stages.

Two or more simple machines put together.

The use of natural biological processes to aid in the decomposition of organic materials.

A group of molecules that each contain the atoms of two or more elements.

When a solution contains a large amount of solute.

A logical result or generalization.

The change of a of a gas into a liquid.

To change from gas to a liquid; for example, from steam to water.

Transfer of heat through direct contact.

A substance through which electric current flows easily.

The controlled use and preservation of natural resources.

The tendency for things to remain unchanged.

A pattern of stars in the sky that humans have observed and named.

An organism that must eat other organisms to obtain energy.

Substances that harm the environment.

The situation within which something is said or done.

The movements of continents.

A decrease in size of a substance due to its atoms moving closer together, often caused by a decrease in temperature.

To identify how things are different.

A factor that is kept the same or constant during an experiment.

The movement of heat through a liquid or gas.

Currents of molten rock the mantle that carry much of the heat to Earth's surface.

The idea that the Sun is at the center of the solar system

The center of the Earth.

The apparent change in motion of wind and water on Earth's surface due to rotation.

A bond in which electrons are shared by the bonded atoms of the molecule.

The high point of a wave.

The outermost layer of Earth.

The exterior layer of Earth's crust (surface); also called tectonic plates

A large movement of water.

In a cell, the jellylike matter that surrounds the nucleus and contains cell structures (called organelles) that carry out the cell's activities.

Information gathered during an experiment or investigation.

The cells produced as a result of cell division, each identical to the parent cell.

An organism that feed off the dead bodies of a once-living organism.

A branching fiber on a nerve cell the receives messages from another nerve cell.

The process by which certain bacteria in the soil change nitrates into gaseous nitrogen, returning it to the air.

A measure of mass in relation to volume.

A factor is changed in response to the independent variable during an experiment.

A picture or an illustration that shows information.

The process in which a waves spread out into a region behind or around a barrier.

Movement of a substance from a region of higher concentration to a region of lower concentration.

The breaking down of food into nutrients that the body's cells can use.

The system of the body that breaks down food into nutrients the body can use and expels leftover wastes.

A solution with the small amount of solute.

Electric current that moves in one direction only.

To become part of a solution.

A process for separating liquids that have different boiling points.

The molecules that contains hereditary information and controls the activities of each cell; found in the chromosomes.

An allele for which the phenotype will always be present.

One gene in a pair that determines the effect of the gene pair.

A trait that will appear in an offspring if one parent contributes it; dominant traits suppress recessive traits.

An investigation in which neither the researchers nor the patients know who is receiving placebos.

The force slowing or stopping the movement of an object through a gas or liquid.

Expressing unstated ideas that are logically connected to give information.

A sudden vibration in the Earth in which plates slip past one another.

The study of the relationship of organisms to their environment.

A community of populations of organisms and the habits and natural resources that affect the community.

A result of an action or condition.

A force applied to an object.

The female reproductive cell; also called the ovum.

A form of faulty logic in which only two choices are presented although other options exist.

An uncommon condition caused by unusually warm temperatures in the tropical Pacific Ocean.

A continuous pathway over which electric current can flow.

The flow that holds electrons in orbit around the nucleus of an atom.

The area of force that surrounds a charged particle.

The entire spectrum of radiation, ranging from radio waves to gamma rays.

A particle with a negative electron that orbits the nucleus of an atom.

The wide range of wavelengths that is made by coiling a wire around a piece of iron and running an electric current through the wire.

The wave motion of alternating electric and magnetic fields.

The wide range of wavelengths over which electromagnetic waves exist.

A wave that can travel through a vacuum.

The relationship between electricity and magnetism.

A negatively charged particle that revolves around the nucleus of an atom.

A substance that cannot be broken down into simpler substances by chemical means; for example, carbon.

A galaxy that looks like a sphere or an elongated sphere of stars.

An organism in its early stage of development.

The body system made up of endocrine glands; these glands secrete hormones into the bloodstream to regulate body processes.

A cell organelle that produces lipids, breaks down chemicals, and transports proteins for delivery to all of a cell

A reaction in which more energy is absorbed than is released.

The ability to do work.

A model of the energy flow in an ecosystem.

The energy levels at which electrons orbit the nucleus of an atom.

The tendency of a system to become randomly disorganized.

All the living and nonliving things that affect an organism's life in some way.

The study of how human beings interact with their environment.

A specialized protein that breaks down organic molecules.

The point on Earth's surface directly above the focus of an earthquake.

The rapid spread of an infectious disease through an entire population.

Chemical tag covering the genome.

A condition in which change takes place in equal and opposite ways.

The gradual wearing away and moving of rock, soil, and sand along Earth's surface.

Mistake in an investigation, including inaccuracy of measuring instruments and sampling.

An organism composed of one or more cells containing a nucleus and organelles.

To examine something in order to judge its significance.

The change of a liquid to a gas.

Observations and data from experiments that support or oppose a stated point of view.

A series of changes that occur over time.

The process in which waste products are removed from the body.

A reaction in which more energy is released than absorbed.

An increase in size of a substance due to its atoms moving farther apart, often caused by an increase in temperature.

A procedure that is designed to test a hypothesis

The addition of newly acquired evidence to facts that are already known.

The dying off of an entire plant or animal species.

Something that can be proven true.

Widespread starvation.

An energy source derived from primarily animal products.

A break in the Earth's crust.

Errors in reasoning.

A type of cellular respiration not requiring oxygen, in which food is broken down into carbon dioxide and alcohol, with the release of energy.

The developing stage of a baby.

A tool to separate a mixture.

A process for separating a mixture.

The splitting of the nucleus of an atom.

The theory that the universe will at some future time reach a size and stay at that size.

The part of the plant in which reproduction occurs.

In Earth science, the point beneath Earth's surface where the rocks break and move to start an earthquake.

The transfer of energy from one organism to the next, each organism consuming the previous one.

The complex pattern of energy transfer in a ecosystem; consisted of many interrelated food chain.

Any push or pull that can affect an object either in motion or at rest.

A trace remain of an organism of a past geological age.

Fuel, such as petroleum, coal, and natural gas, that are used to produce energy for industrialized societies.

Two children who develop from two eggs fertilized by two sperm during the reproductive cycle.

The temperature at which a liquid changes into a solid.

The number of waves that pass a given point in a given amount of time.

A force that slows a moving object.

The boundary between two air masses.

The combining of two atomic nuclei to form one nucleus.

A collection of dust, gas, and stars held together by gravity.

A high-energy electromagnetic wave.

The state of matter that has no definite shape or volume; for example, the air.

A vast cloud of gas and dust out of which a star may form.

A strand of DNA that carries information for a specific trait.

A device that converts mechanical energy to electrical energy.

A disease, disability, or difference caused by an abnormal gene.

The study of how characteristics are passed from one organism to another.

All the genetic information about a single individual or species as coded by the DNA that make up its chromosomes.

The genetic makeup of an organism.

The movement of elements from one chemical storehouse to another.

The study of distribution of chemical elements in Earth's crust.

The study of the composition and structure of Earth.

Energy that comes from Earth's hot interior.

A star that is not as massive as a blue star, but has run out of hydrogen, resulting in the inner core chrinking and the outer core expanding.

Special organs to take oxygen out of water.

A large mass of moving ice.

An organ that secretes chemicals to be used by the body.

The trend toward higher average temperatures on Earth's surface.

A group of older stars that looks like a ball of stars.

A simple sugar that is used to produce energy in plants.

A cell organelle that receives proteins from the endoplasmic reticulum and modifies them for different functions.

A physical representation of data.

The energy an object possessbecause of its gravity.

A force of attraction between two objects that is due to their mass.

The natural heating of a planet by the process of atmospheric gases trapping heat energy.

A gas that prevents the greengouse effect by absorbing infrared reflection.

A column of the Periodic Table that lists elements that have the same number of electrons in their outermost energy shell.

The place in which an organism lives.

The time needed for half of the nuclei in a sample of radioactive material to decay into another substance by giving off nuclear particles or energy.

The measure of force needed to break a substace.

A form of faulty logic in which a conclusion is based on insufficent evidence.

Energy of moving atoms.

The left or right half of the human brain.

A chemical that kills plants.

An animal that eats plants.

A non-unifom mixture, such as oil and vifegar.

The tendency of a system to achieve a relatively stable equilibrium.

A uniform mixture, such as salt and water; also called a solution.

Body parts from different organisms with a common genetic heritage that have similar structure but perform different functions; for example a bird's wing and a human's arm.

A chemical prodyced within the body that regulates body function.

An organism on which a parasite lives.

The measure of water vapor in the air.

A large tropical storm with average wind speeds of at leaset 74 miles per hour.

An organism that carries both the dominant and recessive versions of a particular trait.

A compound composed of only carbon and hydrogen.

Electrical power produced from the mechanical energy found in moving water.

A reasonable explanation of evidence or a prediction based on evidence.

Two children who were formed from the same fertilized egg.

A type of rock formed when hot liquid rock cools; for example, granite.

Molecules, cells, and organs that work together to defend the body against pathogens.

A process in which the body receives a vaccine.

A fact or idea that is suggested by stated information.

To suggest something without actually stating it.

The burning of solid wastes.

A simple machine consisting of a flat, slanted surface.

A pattern of inheritance in which a trait appears as a blend when dominant and recessive versions of it are inherited.

A type of metamorphosis that that takes place in three stages.

A factor that is changed by a scientist during an experiment.

The tendency of an object to stay at rest or in motion unless acted upon by an outside force.

The presence of a pathogen inside the body.

To figure out something that is suggested by stated information.

A fact or idea that you figure out based on stated information.

Energy in the electromagnetic radiation spectrum with wavelengths longer than those of visible light and shorter than those of radio waves.

The solid iron and nickel center of the Earth.

Material that protects against electric shock.

A plant or animal that is not native to an area and has a negative effect on that area.

An animal with no backbone or skull.

A muscle over which a person has limited control.

An atom that has taken on a negative or positive charge by gaining or losing electrons.

The bond between two or more ions (atoms in which one or more electrons have been gained or lost).

The region of Earth's atmosphere that reflet radio waves toward the ground.

A galaxy that differs from the two basic shapes of galaxies.

Information that includes any facts that do not directly a person's decision.

Compounds that have the same number and types of atoms (and thus the same chemical formula) but a different arrangement of atoms and different properties.

The place where one bone meets another.

A unit of work.

The energy an object has because of its motion.

The most general classification of an organism.

A place where solid wastes are buried.

Natural formations that occur on Earth.

A wormlike creature that begins the process of complete metamorphosis.

Magma, or molten rock, that breaks through Earth's surface in a volcanic eruption.

A description of the probability of something happening.

Law states that energy can be transferred but cannot be created or destroyed.

Law that states that matter cannot be created or destroyed.

A property of nature that does not change.

The site of food production in a plant.

A simple machine in which a small force times a large distance at one end becomes a larger times a small distance at the other end.

The stages of life that all living things go through: beginning, growth, maturity, decline, and death.

See biology.

A tough strand of connective tissue.

The range of electromagnetic wavelengths that humans can visibly see.

The distance that light travels in one year: about 6 million miles.

A factor that limits the size of a population.

The reactant that is used up first in a chemical reaction.

An energy-storing fat.

The state of matter that has a definite volume but has a definite shape; for example, water at room temperature.

An object to which force is being applied.

A wave that pushes and pulls molecules back and forth parallel to its direction of travel; for example, sound waves.

An event in which Earth moves between the sun and the moon and casts a shadow on the moon.

A special organelle in an animal cell that gets rid of waste materials, protects the cell from foreign invaders, and destroys worn-out or damaged organelles.

A device that is designed to make work easier.

Hot liquid rock beneath Earth's surface.

A trait in which an object attracts and repels another object.

The central topic of a paragraph, passage, or diagram.

Semi-solid layer of rock found under the crust.

The amount of matter an object contains.

Anything that has weight and takes up space.

The sum of an object's kinetic and potential energy.

A form of cell division by which a single cell divides into four daughter cells.

The process by which a solid turns into a liquid.

The temperature at which a solid changes into a liquid.

The growth and release of a mature egg.

The layer of Earth's atmosphere in which air temperature drops with increasing altitude.

All the chemical processes taking place in a living organism.

A type of rock formed when rock is subject to extreme heat or pressure; for example, marble.

The process in which insects and amphibians go through the stages of life.

A bright streak of light in the night shy caused by a meteoroid burning as it enters Earth's atmosphere.

A fragment of a meteor that is found on the surface of Earth.

The study of the atmosphere.

To move from one place to another.

A turning point or points at which everything changes.

The spiral galaxy in which our sun is located.

See Vitamin.

Inorganic substances needed in trace amounts for growth and health.

A bean-shaped organelle that breaks down the chemical bonds of food molecules.

A form of cell division by which a single cell divides into two identical cells.

A mechanical combination of substances in which each substance keeps its own properties; for example, gravel, air, mayonnaise.

A representation of facts or information.

A substance made of two atoms bonded together.

The process through which an organism sheds its exoskeleton.

An object's mass multiplied by its velocity, or its speed in a straight line.

A solid, spherical object that orbits a planet.

An organism that consists of more than one cell.

A contracting tissue that is responsible for bone movement.

A change in an organism's DNA that causes a change in an inherited characteristic.

A relationship between two organisms in which both organisms benefit.

A gaseous fossil fuel.

Materials formed in nature that are useful to humans.

The idea that individuals with favorable traits are the most likely members of a species to survive, reproduce, and pass on those traits.

A reaction to change in a way that brings it back to its original state.

Electrical signals that travel to and from nerve cells throughout the body.

A bundle of nerves that transmits information in the body.

The communications and control system of an organism consisting of interconnected nerves.

A nerve cell that makes up brain tissue.

When a solution has a pH of 7.

A particle in the nucleus of an atom that has no electrical change.

A very dense small star made up entirely of neutrons from the leftover materials near the center of a supernova.

States that an object will tend to stay at rest or in motion unless acted by an outside force; also known as inertia.

States that the greater the mass of an object, the greater the force needed to move that object.

States that for every force applied to an object, an equal force acts in the opposite direction.

The process by which bacteria covert nitrogen in the soil to ammonia, nitrite, and nitrate, a form of nitrogen that plants can use.

The continuous circulation of nitrogen through the biosphere primarily through the action of bacteria, precipitation, and decomposition.

A process by which certain bacteria take nitrogen from the atmosphere and combine it with other substances into a form that other plants can use.

A material in which electrons cannot be made to flow.

Resources that cannot be replaced or that take hundreds or thousands of years to replace.

A plant that has no specialized tissue to transport water and nutrients to parts of the plant.

The energy released during nuclear fission or fusion reactions, generally used to produce electricity.

The splitting of atomic nucleus into two smaller nuclei and two or three neutrons, releasing large amounts of energy.

The force that holds neutrons and protons together in the nucleus of an atom.

In a cell, the layer of matter that separates the nucleus from the cytoplasm.

A facility that generates electricity by using radioactive fuel, which explodes in a nuclear chain reaction.

A device in which controlled chain reactions are carried out.

A body within the nucleus of a cell that is responsible for making protein.

In life science, the part of a cell that controls the cell's activities; in physical science, an atom's small, dense core, which consists of protons and neutrons.

A nerve cell, the basic unit of the nervous system.

A chemical involved in communication between neurons or a neuron and a muscle.

A substance, found in food, that is necessary for growth and health of an organism; for example, proteins, carbohydrates, fats, minerals, and vitamins.

The study of the health value of food.

A smaller version of an adult insect.

The study of Earth's oceans.

An animal that eats both plants and animals.

A small group of stars that is located along the spiral disk of a spiral galaxy.

The theory that the universe will continue to slowly expand forever.

A personal belief that is often on a person's own value system.

The path in which a planet travels around the Sun.

The tendency of properties and behavior to be predictable.

A group of different tissues that perform together to perform a specific function or functions.

A group of organs that work together.

A specialized structure within the cytoplasm of a cell that performs a special life activity.

A carbon-containing compound.

The study of carbon.

A molecule that contains carbon combined with nitrogen, hydrogen, or oxygen; the building blocks of all living organisms.

A living thing.

The path taken by a planet or moon around the focus of the system to which it belongs; for example, Earth's orbit around the Sun.

Diffusion of a solvent, often water, through a semipermeable membrane until its concentration is equal on both sides of the membrane.

The liquid outer layer of Earth's core.

A form of faulty logic in which something is so simplified so much that it becomes incorrect.

A reaction in which an element loses electrons; often in oxidation, the element reacts with oxygen; for example, iron reacts with oxygen to form iron oxide (rust).

A type of oxygen gas that surrounds Earth and absorbs ultraviolet rays.

The study of prehistoric animal and plant life through the analysis of fossil remains.

The massive supercontinent that split into the seven continents.

A circuit in which there is more than one path for electric current to take.

A relationship that helps one organism while causes harm to the other.

The cell undergoing mitosis and cell division.

A long, narrow tunnel, charged with electric and magnetic fields, used to accelerate and collide particles in order to release energy and create new particles.

A harmful bacterium, virus, or fungus that invades the human body.

A row of the Periodic Table that contains elements that have the same number of energy shells.

An arrangement of the elements according to their properties and atomic number.

A liquid fossil fuel; also called oil.

Range of numbers from 0 to 14 that indicates the relative acidic or basic character of a solution: 7 indicates a neutral solution; numbers lower than 7 indicate an acid; numbers higher than 7 is a base.

Matter in the form of a solid, liquid, or gas.

A physical change to the shape of a substance.

The three forms of substance: solid, liquid, and gas.

In genetics, the observable physical characteristics of an individual organism.

The chemical process by which green plants convert water and carbon dioxide into food and oxygen using energy absorbed from sunlight or other light.

A change to a substance that does not change its chemical identity.

Properties that can be observed without changing the chemical identity of the substance.

A process that breaks down rocks but does not change the composition of the rock.

The female reproductive structure in a flowering plant.

A special tissue through which a developing placental embryo receives nourishment from its mother.

A large celestial body that revolves around a star; for example, Earth and Jupiter.

A theory that explains how Earth's crust is formed, changes over time, and is destroyed.

A grain that contains the male sex cell of a flowering plant.

The process by which flowering plants reproduce.

Any form of contamination that affects the quality of life.

A hydrocarbon that contains a large of carbon atoms.

A group of organisms of the same species that live in the same area.

The number of people who live in a specific area.

Energy stored in the position of an object at rest.

The rate at which work is done.

When a solute begins to come out of a solution.

An animal that gets its food by hunting and killing for it.

A guess based on facts.

A triangular piece of glass that breaks light into a spectrum of colors.

An organism that capture the sun's energy and make their own food.

A substance formed as a result of a chemical reaction.

An organism whose cells do not contain a nucleus and other specialized cell structure.

A molecule that is necessary for cell growth and repair and sometimes energy.

A particle in the nucleus of an atom that has a positive electric change.

A simple machine consisting of a rope that fits into a wheel that can be moved.

A neutron star that spins, sending out beams of pulsing radiation.

A fore of rapid evolution in which species suddenly appear or disappear on Earth.

A diagram that shows the possible combinations of genotypes two parent organisms can produce.

A resting insect in the third stage of complete metamorphosis.

A substance made of identical atoms or molecule.

A subatomic particle that make up the protons and neutrons.

The movement of heat without particles.

A property of some elements that involves giving off particles or energy from the nucleus until a more stable element is produced.

Methods of using the decay rate of materials and soil to learn how long they have been there.

A substance that is an ingredient of a chemical reaction.

The speed at which a chemical reaction takes place.

A gene that has no effect if a dominant gene is present.

The breaking down of trash into its component substances and reusing them in new products.

The smallest and coolest of stars, having the longest lifetime of all star.

A giant star that glows a cool, red color.

The process in which a wave bounces off a smooth surface.

A rapid, automatic response to a condition in an organism's environment; for example, squinting in strong light.

The process in which a wave crosses a boundary and begins to move in a slightly different direction.

Information that includes facts that directly affect a person's decision.

Resources that can be used and then replaced over a relatively short period of time.

The process by which an organism produces future generation of its own kind.

A lake created by a dam.

A force that opposes, or slows motion; in reference to electricity, the opposition a material offers to the free flow of electric current.

A material that people need from Earth.

The process of burning trash to create electricity.

The process by which living things take in oxygen and release carbon dioxide to obtain energy.

The system of the body involved in exchanging oxygen for carbon dioxide.

The reaction of an organism to stimulus.

To use different words and phrases to express the same idea.

A planet's complete trip around the Sun.

To move in a circular or elliptical path around a central object; for example, Earth revolves around the Sun.

A virus that causes certain types of colds.

A cell organelle on which the amino acids combine to make protein.

A measure of the amount of energy released by an earthquake; the Richter scale starts at 0 and although it has no upper limit, no earthquake recorded has measured stronger than a 9.

The part of a plant that anchors it in the ground and absorbs water and minerals from the soil.

The long extensions of the root that serve as the main point of entrance for water into the root.

To turn on its own central axis.

A neutral compound with a pH of 7.0 that results from the chemical combination of an acid and a base; for example, sodium chloride (table salt).

A type of fat that is solid at room temperature.

A conclusion, based on evidence, that scientists agree on.

Organized ways of solving problems; the processes scientists use for getting information and testing ideas.

The movement of the sea floor crust away from the mid-ocean ridges, where new crust is pushing up from the mantle.

A type of rock formed by the hardening of particles of sand, mud, clay, or sediments; for example, sandstone.

Vibrations caused by movement of rock during an earthquake.

A material in which only a small amount of electric current can be made to flow.

The means by which animals get information about their environment: sight, hearing, taste, touch, and smell.

The order in which things happen.

A circuit in which there is only one path for electric current to take.

A form of reproduction in which genetic material from two parents is combined in the offspring.

An element common in Earth's crust.

a device to do work (example: lever).

The frame of the human body.

A bone that protects the brain and other organs in the head.

The behavior of animals of the same species as they live together.

Instructions that tell a computer how to perform a task.

A mixture of tiny rock fragments and organic materials produced by living things.

A device that produces electricity when sunlight strikes it.

Energy from the sunlight.

A cloud of interstellar gas and dust from which the solar system is formed.

The sun and the objects that revolve around it, such as the planets and their moons.

A state of matter that has a definite shape and takes up a definite amount of space.

Related to the amount of a solute that will dissolve in a given amount of solvent at a given temperature and pressure.

The substance in a solution that is dissolved in a solution.

The substance being dissolved in a solution; for example, salt in salt water.

A type of mixture in which the ingredients are distributed evenly throughout.

The substance doing the dissolving in a solution; for example, water in salt water.

A sensation caused by vibrations and perceived by hearing.

Vibrations transmitted through substances in waves with frequencies that can be heard.

Unmanned spacecraft used for the exploration of space.

A group of organisms with similar characteristics that can interbreed to produce fertile offspring.

A device used to analyze what things are made of.

The male sex cell.

A galaxy that has a huge core of stars surrounded by spiral arms.

A tiny reproductive cell.

A joint injury in which the ligaments are stretched or torn.

A type of cancer that looks raised, pink spots or growths that may be open at the center.

The male reproductive structure in a flowering plant.

Electricity in which electrons are transferred from one object to another.

The zone between two air masses, caused when the masses stop moving.

The part of a plant that holds the leaves up towards the sunlight and transports water and minerals from the roots to the leaves.

Anything in the environment that influences the nervous system; for example, the sight of a snake or the smell of coffee.

Tiny openings in a leaf that allows gases to enter and exit the leaf.

The second layer of Earth's atmosphere; contains ozone gas.

A diagram using symbols representing the arrangement of atoms in a molecule.

A long tube through which pollen moves from the stigma to the ovary in a flowering plant.

Particles smaller than protons, neutrons, and electrons; also called elementary particles.

Matter of one particular type.

To condense or shorten a larger amount of information into a few sentences.

A conductor in which there is no electrical resistance.

A very large star.

A flash of light caused by the explosion of a massive blue star that has become too hot.

Observations, measurements, and other facts that back up a conclusion.

The space between two neurons and a muscle across which nerve impulses are transmitted.

A type of list that organizes information in rows and columns.

The use of knowledge, materials, and tools to solve human problems and to provide for human needs and wishes.

Large fragments of Earth's crust and an upper mantle that fit together like a puzzle piece.

The measure of heat energy; the measure of the warmth of the air in Earth's atmosphere.

A strong, fibrous connective tissue that connects bones and muscles.

The outermost layer of Earth's atmosphere in which the temperature rises with the altitude.

An illustration that shows when a series of events took place and the order in which they occurred.

A group of similar cells that have a similar function; for example, muscle tissue.

The sentence that contains the main idea in a paragraph.

The tube through which air passes from the back of the mouth to the lungs; also called the windpipe.

An inherited characteristic such as hair color or blood type.

An electric device used to amplify, detect, or switch electric current.

A wave in which the disturbance is at right angles to the direction of the wave's travel; for example, light waves.

In a food chain, the position occupied by each species.

Dense forest found near the equator where the climate is hot and wet.

The layer of Earth's atmosphere that is closest to the ground.

The low point of a wave.

A type of light with wavelengths too short to be visible to the human eye; also known as black light.

A type of harmful energy in the sunlight.

An organism that consists of a single cell.

A fact or idea that is taken for granted and not actually stated.

A woman's womb, in which her unborn baby develops.

An injected dose of dead or weakened disease-causing agent. The body reacts to a vaccination by forming antibodies to fight the disease.

A large compartment in a plant cell that stores water and other liquids.

A space that contains no matter.

A principle or a quality that a person believes is important.

The change of a liquid to a gas.

A plant that has specialized tissue for transporting water and nutrients to parts of the plant.

A blood vessel that carries blood toward the heart.

The rate of motion of an object in a certain direction.

One of the lower chambers of the heart.

An animal with a backbone and a skull.

A membrane-covered compartment near the cell membrane that stores proteins and other organic substances.

A tiny particle of genetic material with a protein covering.

See Light.

A chemical that is necessary for proper body growth, body activity, and the prevention of certain diseases.

A place where magma breaks through Earth's surface.

Unit of measurement for the voltage of electricity.

The energy needed to move an electron or other charged particle, measured in volts.

The amount of space taken up by a substance or object.

A muscle that a person can consciously control.

A classification of animals who can control their own internal body temperatures.

The circulation of water on Earth through evaporation from the surface into the atmosphere and back to the surface through precipitation.

A disturbance that travels through space or matter; for example radio waves.

The distance from the top of one wave to the top to the next wave.

The state of the atmosphere at any given time with respect to temperature, moisture, wind direction and velocity, and air pressure.

A map showing where cold, warm, and stationary front are, as well as areas of high and low pressure.

The process by which large rocks are broken down in place into smaller rocks; may be chemical or mechanical.

A simple machine composed of two objects that turn in a circular motion on the same center, multiplying both force and speed.

A small, hot star that is the leftover core of a giant or supergiant.

Moving air.

The process in which an object moves in response to an applied force.

The study of animals.

A fertilized egg resulting when the sperm from the father joins with the egg produced by the mother.