AP Biology - Chapter 03 (Water and the Fitness of the Environment) Flashcards

191327826	acid	A substance that increases the hydrogen ion concentration of a solution.	0
191327827	acid precipitation	Rain, snow, or fog that is more acidic than pH 5.6.	1
191327828	adhesion	The attraction between different kinds of molecules.	2
191327829	aqueous solution	A solution in which water is the solvent.	3
191327830	base	A substance that reduces the hydrogen ion concentration of a solution.	4
191327831	buffer	A substance that consists of acid and base forms in a solution and that minimizes changes in pH when extraneous acids or bases are added to the solution.	5
191327832	calorie (cal)	The amount of heat energy required to raise the temperature of 1 g of water by 1°C; also the amount of heat energy that 1 g of water releases when it cools by 1°C. The Calorie (with a capital C), usually used to indicate the energy content of food, is a kilocalorie.	6
191327833	Celsius scale	A temperature scale (°C) equal to 5/9 (°F - 32) that measures the freezing point of water at 0°C and the boiling point of water at 100°C.	7
191327834	cohesion	The binding together of like molecules, often by hydrogen bonds.	8
191327835	colloid	A mixture made up of a liquid and particles that (because of their large size) remain suspended in that liquid.	9
191327836	evaporative cooling	The property of a liquid whereby the surface becomes cooler during evaporation, owing to a loss of highly kinetic molecules to the gaseous state.	10
191327837	heat	The total amount of kinetic energy due to molecular motion in a body of matter. Heat is energy in its most random form.	11
191327838	heat of vaporization	The quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state.	12
191327839	hydration shell	The sphere of water molecules around each dissolved ion.	13
191327840	hydrogen ion	A single proton with a charge of +1. The dissociation of a water molecule (H2O) leads to the generation of a hydroxide ion (OH-) and a hydrogen ion (H+).	14
191327841	hydrophilic	Having an affinity for water.	15
191327842	hydrophobic	Having an aversion to water; tending to coalesce and form droplets in water.	16
191327843	hydroxide ion	A water molecule that has lost a proton.	17
191327844	joule (J)	A unit of energy: 1 J = 0.239 cal; 1 cal = 4.184 J.	18
191327845	kilocalorie (kcal)	A thousand calories; the amount of heat energy required to raise the temperature of 1 kg of water by 1°C.	19
191327846	kinetic energy	The energy of motion, which is directly related to the speed of that motion. Moving matter does work by imparting motion to other matter.	20
191327847	molarity	A common measure of solute concentration, referring to the number of moles of solute per liter of solution.	21
191327848	mole (mol)	The number of grams of a substance that equals its molecular weight in daltons and contains Avogadro's number of molecules.	22
191327849	molecular mass	The sum of the masses of all the atoms in a molecule; sometimes called molecular weight.	23
191327850	pH	A measure of hydrogen ion concentration equal to -log [H+] and ranging in value from 0 to 14.	24
191327851	polar molecule	A molecule (such as water) with opposite charges on opposite sides.	25
191327852	solute	A substance that is dissolved in a solution.	26
191327853	solution	A liquid that is a homogeneous mixture of two or more substances.	27
191327854	solvent	The dissolving agent of a solution. Water is the most versatile solvent known.	28
191327855	specific heat	The amount of heat that must be absorbed or lost for 1g of a substance to change its temperature by 1°C.	29
191327856	surface tension	A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules.	30
191327857	temperature	A measure of the intensity of heat in degrees, reflecting the average kinetic energy of the molecules.	31