front 1 covalent bond | back 1 chemical bond that involves the sharing of electron pairs between atoms |
front 2 ionic bond | back 2 chemical bond that involves the attraction between oppositely charged ions |
front 3 hydrogen bond | back 3 a weak bond between two molecules due to the electrostatic attraction between a hydrogen atom in one molecule and an atom of oxygen, nitrogen or fluorine in the other molecule |
front 4 halocline | back 4 a layer of water below the mixed surface layer where a rapid change in salinity can be measured as depth increases |
front 5 thermocline | back 5 a layer between two layers of water with different temperatures |
front 6 gradient | back 6 the rate of change in the y-axis value as the x-axis value increases |
front 7 thermal insulator | back 7 a substance which reduces the rate of transfer of thermal energy |
front 8 pycnocline | back 8 a layer of water between two layers of water with different densities |
front 9 earthquake | back 9 a sudden release of energy inside the Earth that creates seismic waves |
front 10 mid-ocean ridge | back 10 a mountain range with a central valley on an ocean floor at the boundary between two diverging tectonic plates, where new crust forms from upwelling magma |
front 11 divergent boundary | back 11 where two tectonic plates are moving away from each other |
front 12 convergent boundary | back 12 when two or more tectonic plates come together |
front 13 subduction | back 13 the process where one lithospheric plate slides past below another at a convergent plate boundary |
front 14 trench | back 14 a long, narrow and deep depression on the ocean floor with relatively steep sides |
front 15 volcano | back 15 a mountain or hill with a crater or vent through which lava, rock fragments, hot vapour and gas are being forced from the Earth's crust |
front 16 tsunami | back 16 a seismic sea wave created by an underwater earthquake or volcanic event |
front 17 hydrothermal vent | back 17 an area where cold ocean water that has seeped into the Earth's crust is superheated by an underlying magma and forced through the vents in the ocean floor |
front 18 transform boundary | back 18 when two plate are moving in an antiparallel direction, creating friction between them |
front 19 abyssal plain | back 19 a flat, sandy region of the ocean floor found between trenches and the continental rise |
front 20 semi-diurnal | back 20 occurring twice daily |
front 21 diurnal | back 21 occurring daily |
front 22 coriolis effect | back 22 a force that results from the Earth's rotation that causes objects or particles in motion to deflect to the right in the Northern Hemisphere and to the left in the Southern Hemisphere |
front 23 thermohaline circulation | back 23 large-scale ocean circulation caused by density differences due to temperature and salinity changes in the world's ocean |
front 24 downwelling | back 24 the downward movement of water in the sea due to density differences |
front 25 community | back 25 all the different populations interacting in one habitat at the same time |
front 26 competition | back 26 a relationship between two organisms where both species are negatively is affected as they are trying to use the same resource |
front 27 food chain | back 27 a way to describe the feeding relationships between organisms |
front 28 decomposers | back 28 bacteria and fungi which break down dead organic matter and release the nutrients back into the environment |
front 29 food web | back 29 a way to show all the different feeding relationships in an ecosystem |
front 30 trophic level | back 30 the position on organism occupies in the food chain or web |
front 31 apex predator | back 31 an organism at the end of the food chain which has no natural predators |
front 32 respiration | back 32 the process by which all living things release energy from their food by oxidising glucose |
front 33 eutrophication | back 33 the process by which a body of water becomes enriched in dissolved nutrients that stimulate the growth of producers, usually resulting in the depletion of dissolved oxygen |
front 34 marine snow | back 34 particles of organic material that fall from surface layers to the deeper ocean |