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Chapter 2 Vocab
Biology
Term | Definition |
---|---|
acid | any compound that increases the number of hydronium ions when dissolved in water; acids turn blue litmus paper red and react with bases and some metals to form salts |
activation energy | the minimum amount of energy required to start a chemical reaction |
adhesion | the attractive force between two bodies of different substances that are in contact with each other |
aqueous solution | a solution in which water is the solvent |
atom | the smallest unit of an element that maintains the chemical properties of that element |
atomic number | the number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element |
base | any compound that increases the number of hydroxide ions when dissolved in water; bases turn red litmus paper blue and react with acids to form salts |
buffer | a solution made from a weak acid and its conjugate base that neutralizes small amounts of acids or bases added to it |
capillarity | the attraction between molecules that results in the rise of a liquid in small tubes |
catalysis | the acceleration of a chemical reaction by a catalyst |
chemical bond | the attractive force that holds atoms or ions together |
chemical reaction | the process by which one or more substances change to produce one or more different substances |
cohesion | the force that holds molecules of a single material together |
compound | a substance made up of atoms of two or more different elements joined by chemical bonds |
concentration | the amount of a particular substance in a given quantity of a mixture, solution, or ore |
covalent bond | a bond formed when atoms share one or more pairs of electrons |
electron | a subatomic particle that has a negative charge |
element | a substance that cannot be separated or broken down into simpler substances by chemical means; all atoms of an element have the same atomic number |
energy | the capacity to do work |
enzyme | a molecule, either protein or RNA, that acts as a catalyst in biochemical reactions |
hydrogen bond | the intermolecular force occurring when a hydrogen atom that is bonded to a highly electronegative atom of one molecule is attracted to two unshared electrons of another molecule |
hydronium ion | an ion consisting of a proton combined with a molecule of water; H3O+ |
hydroxide ion | the OH- ion |
ion | an atom, radical, or molecule that has gained or lost one or more electrons and has a negative or positive charge |
ionic bond | the attractive force between oppositely charged ions, which form when electrons are transferred from one atom to another |
isotope | an atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass) |
mass | a measure of the amount of matter in an object |
mass number | the sum of the numbers of protons and neutrons in the nucleus of an atom |
matter | anything that has mass and takes up space |
metabolism | the sum of all chemical processes that occur in an organism |
molecule | a group of atoms that are held together by chemical forces; a molecule is the smallest unit of matter that can exist by itself and retain all of a substance's chemical properties |
neutron | a subatomic particle that has no charge and that is located in the nucleus of an atom |
nucleus | an atom's central region, and made up of protons and neutrons |
orbital | a region in an atom where there is a high probability of finding electrons |
oxidation reaction | a chemical reaction in which a reactant loses one or more electrons such that the reactant becomes more positive in charge |
pH scale | a range of values that are used to express the acidity or alkalinity (basicity) of a system; each whole number on the scale indicates a tenfold change in acidity; a pH of 7 is neutral, a pH of less than 7 is acidic, and a pH of greater than 7 is basic |
polar | describes a molecule in which the positive and negative charges are separated |
product | a substance that forms in a chemical reaction |
proton | a subatomic particle that has a positive charge and that is located in the nucleus of an atom; the number of protons in the nucleus is the atomic number, which determines the identity of an element |
reactant | a substance that participates in a chemical reaction |
redox reaction | a reaction in which electrons are transferred between atoms; also known as an oxidation-reduction reaction |
reduction reaction | a chemical change in which electrons are gained, either by the removal of oxygen, the addition of hydrogen, or the addition of electrons |
saturated solution | a solution that cannot dissolve any more solute under the given conditions |
solute | in a solution, the substance that dissolves in the solvent |
solution | a homogeneous mixture throughout which two or more substances are uniformly dispersed |
solvent | in a solution, the substance in which the solute dissolves |