The identifying number of an element which indicates the number of protons in each atom of that particular element.
What is the atomic number?
100
A strong chemical bond in which two atoms share one or more pairs of outer-shell electrons.
What is a covalent bond?
100
A substance containing two or more elements joined together by covalent or ionic bonds in a fixed ratio.
What is a compound?
100
The sticking together of molecules (i.e. water molecules) of the same kind, often by hydrogen bonds.
What is cohesion?
100
A substance that increases the hydrogen ion concentration in a solution.
What is an acid
200
One of several atomic forms of an element, each with the same number of protons, but a different number of neutrons.
What is an isotope?
200
Bonds hold_______. When bonds are broken, ______ is released.
What is energy?
200
Two or more atoms, of the same or different elements, held together by covalent bonds.
What is a molecule?
200
The attraction between different kinds of molecules. (i.e. the attraction of water molecules to a surface).
What is adhesion?
200
A chemical substance that resists changes in pH by accepting hydrogen ions from or donating hydrogen ions to solutions.
What is a buffer?
300
An atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge.
What is an ion?
300
Any compound resulting from the formation of ionic bonds; also called an ionic compound.
What is a salt?
300
A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.
What is a polar covalent bond?
300
Water resists temperature change. As a result, a pond will hold the heat from the daytime when the temperature of the air cools overnight. Many organisms use this property of water to their advantage and will migrate to ponds overnight to maintain their body temperature throughout the night. What is the property of water illustrated in this example?
Water's high specific heat capacity
300
Decreasing pH of ocean waters due to absorption of excess atmospheric carbon dioxide from the burning of fossil fuels.
What is ocean acidification?
400
An isotope whose nucleus decays spontaneously, giving off particles and energy.
What is a radioactive isotope?
400
A type of weak chemical bond formed when the partially positive hydrogen atom participating in a polar covalent bond in one molecule is attracted to the partially negative atom participating in a polar covalent bond in another molecule.
What is a hydrogen bond?
400
The attraction of a given atom for the electrons of a covalent bond.
What is electronegativity?
400
H2O is the most dense in its _________ phase.
What is liquid?
400
________ causes decreasing pH of lakes, streams, and soil, deterioration of plants, and destruction of ecosystems.
What is acid precipitation?
500
An _______ receives one or more electrons when forming an ionic bond
What is anion?
500
Covalent bonds form between these types of elements.
What are nonmetals?
500
The process by which the action of a solvent causes a molecule to split into simpler groups of atoms, single atoms, or ions.
What is dissociation?
500
H20 has the greatest amount hydrogen bonds in its ______ phase, and the least amount of hydrogen bonds in its _______ phase
Solid; gas
500
A substance with a pH of 13 has _______ times more ________ ions than a substance with a pH of 10.