bio chapter 3

book chapter

polar covalent bond

oxygen is more electronegative than hydrogen, electrons spend more time closer to oxygen

polar molecules

unequal sharing of electrons, overall charge unevenly distributed

cohesion

linkages that make hydrogen bonds hold substances together

surface tension

measure of how different it is to stretch or break surface of liquid

adhesion

clinging of one substance to another

kinetic energy

energy of motion

thermal energy

kinetic energy associated with random movement of atoms and molecules

temperature

average kinetic energy of the molecules in a body of matter, regardless of volume

heat

thermal energy in transfer from one body of matter to another

calorie (cal)

amount of heat it takes to raise the temperature of 1g of water by 1 degree C

kilocalorie (kcal)

1,000 cal, quantity of heat required to raise the temperature of 1 kilogram of water by 1 degree C

specific heat

amount of heat that must be adsorbed or lost for 1g of that substance to change its temperature by 1 degree C

vaporization/evaportation

molecules move fast enough to overcome and depart from liquid as gas

heat of vaporization

quantity of heat a liquid must absorb for 1g of it to be converted from liquid to gaseous state

evaporative cooling

liquid evaporates, surface of where liquid was cools down

solution

liquid tyat is completely homogenous mixture of two or more substances

solute

substance that is dissolved

solvent

dissolving seen of solution

aqueous solution

solute is dissolved in water, water is solvent

dehydration shell

sphere of water moleucles around each dissolving ion

hydrophilic

substance that has affinity for water

hydrophobic

no affinity for water, cells r too big to dissolve in water

molecular mass

sum of the masses of all atoms in molecule

mole (mol)

exact number of objects

Avogadro’s number

6.02 × 10^23

molarity

number of moles solute per life of solution, unit of concentration

hydrogen ion

single proton with charge of +1

hydroxide ion

charge of -1

hydronium ion

proton binds to water molecule

acid

substances that increase hydrogen ion concentration of a solution

base

substance that reduces hydrogen ion concentration

weak acids

reversibly relate and accept back hydrogen ions

pH scale

simple numerical method for expressing the range of H+ concentration

pH

solution is defined as the negative logarithm (base 10) of H+ concentration

buffers

substance that minimizes changes in concentration of H+ and OH- in a solution

ocean acidification

alters delicate balance of conditions for life in oceans