front 1 the chart scientists use to organize and classify all the known elements | back 1 Periodic Table |
front 2 a pure substance that cannot be broken down into simpler substances by chemical reactions | back 2 Element |
front 3 the one- or two-letter representation of an element | back 3 Element Symbol |
front 4 the number of protons in the nucleus of an atom | back 4 Atomic Number |
front 5 approximately equal to the number of protons and neutrons | back 5 Atomic Mass |
front 6 one of the horizontal rows in the periodic table | back 6 Period |
front 7 vertical columns of elements (families) on the periodic table with similar valence electron configurations and similar properties | back 7 Groups |
front 8 vertical columns of elements (groups) on the periodic table with similar valence electron configurations and similar properties | back 8 Family |
front 9 a set of symbols used to describe the elements within a substance | back 9 Chemical Formula |
front 10 a shiny, dense substance that easily conducts heat and electricity | back 10 Metals |
front 11 elements that are poor electrical conductors and tend to accept electrons easily | back 11 Nonmetals |
front 12 elements that lie between the metals and the nonmetals on the periodic table; these element exhibit both metallic and nonmetallic properties | back 12 Metalloids |
front 13 six elemental gasses that do not naturally react with other elements | back 13 Noble Gases |
front 14 the tendency of two or more chemicals to react | back 14 Reactivity |
front 15 a characteristic of a substance that is measurable or observable during a chemical reaction | back 15 Chemical Property |
front 16 a characteristic used to describe matter that can be observed (such as texture, color, and odor) or measured (such as mass, length, and volume) without changing its composition | back 16 Physical Property |
front 17 a Russian scientist who organized and classified the elements based on similar physical and chemical properties; his work was the basis for the modern periodic table of the elements | back 17 Dmitri Mendeleev |
front 18 a subatomic particle with a positive charge that is located in the nucleus of an atom | back 18 Proton |
front 19 the smallest unit of an element that has the properties of that element | back 19 Atom |
front 20 the path or orbit electrons follow around the nucleus of an atom | back 20 Electron Shell |