AP Biology Exam Review Questions and
Answers
Matter
anything that takes up space and has mass
Element
A substance that cannot be broken down into simpler substances
Compound
A substance made up of atoms of two or more different elements joined by chemical bonds
Molecule
two or more atoms held together by covalent bonds
Trace elements
An element indispensable for life but required in extremely minute amounts.
Atom
Basic unit of matter
Neutron
A subatomic particle that has no charge and that is found in the nucleus of an atom
Protons
positively charged subatomic particles found in the nucleus.
Electron
A subatomic particle that has a negative charge and is found outside the nucleus
Atomic number
number of protons
Mass number
the sum of the number of neutrons and protons in an atomic nucleus
Isotopes
Atoms of the same element that have different numbers of neutrons
Potential energy
stored energy that results from the position or shape of an object
Kinetic energy
the energy an object has due to its motion
,Valence electrons
Electrons on the outermost energy level of an atom
Covalent bonds
Bonds created by sharing electrons with other atoms.
Ionic bonds
Formed when one or more electrons are transferred from one atom to another
Hydrogen bonds
Very weak bonds; occurs when a hydrogen atom in one molecule is attracted to the electrostatic
atom in another molecule
Electronegativity
a measure of the tendency of an atom to attract a bonding pair of electrons
Nonpolar covalent bond
A type of covalent bond in which electrons are shared equally between two atoms of similar
electronegativity.
Polar covalent bond
A covalent bond in which electrons are not shared equally
Anion vs Cation
anion is negative, cation is positive
Reactants vs Products
Reactants are substances that start a chemical reaction. Products are substances that are produced in
the reaction.
Chemical equilibrium
In a chemical reaction, the state in which the rate of the forward reaction equals the rate of the
reverse reaction, so that the relative concentrations of the reactants and products do not change with
time.
Cohesion vs Adhesion
cohesion: attraction between molecules of the same substance
adhesion: attraction between molecules of different substances
Surface tension
A measure of how difficult it is to stretch or break the surface of a liquid
solvent
, the substance in which the solute dissolves. Ex: Water
Aqueous solution
a solution in which water is the solvent
Hydrophobic
Water fearing
Hydrophilic
water loving
Hydroxide ion
OH-
Acid
pH less than 7
pH scale
scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution.
Organic chemistry
the study of compounds containing carbon
Hydrocarbons
organic molecules consisting of only carbon and hydrogen
Structural isomer
differ in the covalent arrangements of their atoms
Geometric isomer
isomer with similar bonding patterns differing in the placement of atoms alongside a double covalent
bond
Functional group
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules
and involved in chemical reactions.
Carboxyl group
COOH
Amino group
NH2
Answers
Matter
anything that takes up space and has mass
Element
A substance that cannot be broken down into simpler substances
Compound
A substance made up of atoms of two or more different elements joined by chemical bonds
Molecule
two or more atoms held together by covalent bonds
Trace elements
An element indispensable for life but required in extremely minute amounts.
Atom
Basic unit of matter
Neutron
A subatomic particle that has no charge and that is found in the nucleus of an atom
Protons
positively charged subatomic particles found in the nucleus.
Electron
A subatomic particle that has a negative charge and is found outside the nucleus
Atomic number
number of protons
Mass number
the sum of the number of neutrons and protons in an atomic nucleus
Isotopes
Atoms of the same element that have different numbers of neutrons
Potential energy
stored energy that results from the position or shape of an object
Kinetic energy
the energy an object has due to its motion
,Valence electrons
Electrons on the outermost energy level of an atom
Covalent bonds
Bonds created by sharing electrons with other atoms.
Ionic bonds
Formed when one or more electrons are transferred from one atom to another
Hydrogen bonds
Very weak bonds; occurs when a hydrogen atom in one molecule is attracted to the electrostatic
atom in another molecule
Electronegativity
a measure of the tendency of an atom to attract a bonding pair of electrons
Nonpolar covalent bond
A type of covalent bond in which electrons are shared equally between two atoms of similar
electronegativity.
Polar covalent bond
A covalent bond in which electrons are not shared equally
Anion vs Cation
anion is negative, cation is positive
Reactants vs Products
Reactants are substances that start a chemical reaction. Products are substances that are produced in
the reaction.
Chemical equilibrium
In a chemical reaction, the state in which the rate of the forward reaction equals the rate of the
reverse reaction, so that the relative concentrations of the reactants and products do not change with
time.
Cohesion vs Adhesion
cohesion: attraction between molecules of the same substance
adhesion: attraction between molecules of different substances
Surface tension
A measure of how difficult it is to stretch or break the surface of a liquid
solvent
, the substance in which the solute dissolves. Ex: Water
Aqueous solution
a solution in which water is the solvent
Hydrophobic
Water fearing
Hydrophilic
water loving
Hydroxide ion
OH-
Acid
pH less than 7
pH scale
scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution.
Organic chemistry
the study of compounds containing carbon
Hydrocarbons
organic molecules consisting of only carbon and hydrogen
Structural isomer
differ in the covalent arrangements of their atoms
Geometric isomer
isomer with similar bonding patterns differing in the placement of atoms alongside a double covalent
bond
Functional group
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules
and involved in chemical reactions.
Carboxyl group
COOH
Amino group
NH2
