| A | B |
|---|
| atom | basic unit of matter |
| element | pure substance made of only one atom |
| ion | an atom with an unequal number of protons and electrons |
| isotope | an atom with an unequal number protons and neutrons |
| neutron | a subatomic particle found in the nucleus; no charge |
| proton | a positively charged subatomic particle located in the nucleus |
| electron | orbits the nucleus of an atom; negative charge |
| covalent bond | a bond that results from sharing electrons |
| ionic bond | a bond that results from the transfer of electrons |
| polar molecule | a molecule with a slight charge on each pole |
| atomic number | the number of protons in an atom |
| atomic mass | mass of the protons and neutrons of an atom |
| solute | in a solution, the substance that is dissolved |
| solvent | in a solution, the substance that dissolves the other substance |
| solution | a combination of solute + solvent |
| acid | releases H+ ions; pH of 1 to 6 |
| base | releases OH- ions in water; pH of 8 to 14 |
| homeostasis | maintaining stable internal conditions |
| multicellular | 2 or more cells |
| unicellular | one cell |
| sexual reproduction | requires the union of two cells |
| asexual reproduction | binary fission or cloning |
| hypothesis | an educated guess; it must be testable |
| independent variable | the variable that is manipulated |
| control variable | the variable that is left alone; used for comparison. |
| theory | a concept or idea that has been repeatedly tested; it is widely accepted because there is a lot of evidence to support it |
| dependent variable | the variable that is being measured; what you are trying to figure out |
| hydrophilic | a substance that interacts with water |
| hydrophobic | a substance that does not interact with water. |
| evolution | change over time |
| organelle | a structure within a cell that carries out a specific function |
| tissue | a group of similar cells that perform a similar function. |
| organ | a group of tissues that work together to perform one or more complex functions |
| population | same species, same place, same time |
| community | different species, same place, same time |
| ecosystem | a community of living things and the physical environment with which they interact |
| electronegativity | the measure of the strength of attraction an atom has for electrons that are being shared in a covalent bond |
| polar covalent bond | a covalent bond in which electrons are being shared unequally; results in a slightly negative charge on one end and a slightly positive charge on the other |
| nonpolar covalent bond | a covalent bond in which electrons are shared equally |
| hydrogen bond | a chemical bond that links an already covalently bonded hydrogen atom with a second electronegative atom |
| specific heat | the amount of energy needed to raise the temperature of 1gm of a substance by 1 degree C. |
| cohesion | water's ability to stick to itself |
| adhesion | water's ability to stick to other substances |
| surface tension | an increased attraction of water molecules at the surface to the water molecules below the surface. |
| buffering system | a physiological system that functions to keep pH within normal limits of an organism |
