AP BIO CHAPTER 2|UPDATED&VERIFIED|GUARANTEED SUCCESS

anion A negatively charged ion. atom The smallest unit of matter that retains the properties of an element. atomic nucleus An atom's central core, containing protons and neutrons. atomic number The number of protons in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol. atomic weight The total atomic mass, which is the mass in grams of one mole of the atom. cation An ion with a positive charge, produced by the loss of one or more electrons. chemical bond An attraction between two atoms resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms; the bonded atoms gain complete outer electron shells. chemical equilibrium In a reversible chemical reaction, the point at which the rate of the forward reaction equals the rate of the reverse reaction. chemical reaction A process leading to chemical changes in matter; involves the making and/or breaking of chemical bonds. compound A substance consisting of two or more elements in a fixed ratio. covalent bond A type of strong chemical bond in which two atoms share one pair of valence electrons. dalton A measure of mass for atoms and subatomic particles. double covalent bond A type of covalent bond in which two atoms share two pairs of electrons; symbolized by a pair of lines between the bonded atoms. electron shell An energy level representing the distance of an electron from the nucleus of an atom. electron A subatomic particle with a single negative charge; one or more electrons move around the nucleus of an atom. electronegativity The attraction of an atom for the electrons of a covalent bond. element Any substance that cannot be broken down to any other substance. energy level The different states of potential energy for electrons in an atom. energy The capacity to do work (to move matter against an opposing force). hydrogen bond A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule. ion An atom that has gained or lost electrons, thus acquiring a charge. ionic bond A chemical bond resulting from the attraction between oppositely charged ions. ionic compound Compounds resulting from the formation of ionic bonds, also called a salt. anion A negatively charged ion. atom The smallest unit of matter that retains the properties of an element. atomic nucleus An atom's central core, containing protons and neutrons. atomic number The number of protons in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol. atomic weight The total atomic mass, which is the mass in grams of one mole of the atom. cation An ion with a positive charge, produced by the loss of one or more electrons. chemical bond An attraction between two atoms resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms; the bonded atoms gain complete outer electron shells. chemical equilibrium In a reversible chemical reaction, the point at which the rate of the forward reaction equals the rate of the reverse reaction. chemical reaction A process leading to chemical changes in matter; involves the making and/or breaking of chemical bonds. compound A substance consisting of two or more elements in a fixed ratio. covalent bond A type of strong chemical bond in which two atoms share one pair of valence electrons. dalton A measure of mass for atoms and subatomic particles. double covalent bond A type of covalent bond in which two atoms share two pairs of electrons; symbolized by a pair of lines between the bonded atoms. electron shell An energy level representing the distance of an electron from the nucleus of an atom. electron A subatomic particle with a single negative charge; one or more electrons move around the nucleus of an atom. electronegativity The attraction of an atom for the electrons of a covalent bond. element Any substance that cannot be broken down to any other substance. energy level The different states of potential energy for electrons in an atom. energy The capacity to do work (to move matter against an opposing force). hydrogen bond A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule. ion An atom that has gained or lost electrons, thus acquiring a charge. ionic bond A chemical bond resulting from the attraction between oppositely charged ions. ionic compound Compounds resulting from the formation of ionic bonds, also called a salt.