Ch. 2

Question 1

When do Hydrogen bonds form and what does this cause?

Answer 1

Heat is released when hydrogen bonds form.

Question 2

When do Hydrogen bonds break down and what does this cause?

Answer 2

Heat is absorbed when hydrogen bonds break.

Question 3

Why is water a good solvent.

Answer 3

Polarity. Water has a negative and positive end.

Question 4

Hydrophilic

Answer 4

Water loving

Question 5

Hydrophobic

Answer 5

Water hating. Ex: Oils

Question 6

Ph stands for what?

Answer 6

Potential Hydrogen

Question 7

Elements

Answer 7

Unique forms of matter with specific chemical and physical properties that cannot be broken down into smaller substances by ordinary chemical reactions

Question 8

The 4 elements common to all living organisms.

Answer 8

Oxygen (O)
Carbon (C)
Hydrogen (H)
Nitrogen (N)

Question 9

What is amu?

Answer 9

Atomic Mass Unit or 1 “Dalton” 1.67 x 10^-24

Question 10

Atomic Number

Answer 10

The number of protons in an element

Question 11

Isotopes

Answer 11

Different forms of the same atom that vary only in the number of neutrons they possess

Question 12

Mass Number

Answer 12

The amount of protons and Neutrons in an Element

Question 13

Atomic Mass

Answer 13

The calculated mean of the mass number for its naturally occurring isotopes which often contains a fraction

Question 14

Chemical Reactivity

Answer 14

The ability to combine and to chemically bond with eachother

Question 15

Molecule

Answer 15

Two or more atoms chemically bonded together.

Question 16

Chemical Reaction

Answer 16

Occurs when two or more atoms bond together to form molecules or when bonded atoms break apart

Question 17

Reactants

Answer 17

Substance in the begging reactions

Question 18

Adhesion

Answer 18

is an attraction between different substances, for example, between water and plant cell walls.

Question 19

Cohesion

Answer 19

“Sticky.” Hydrogen Bonds hold water molecules together.

Question 20

Surface Tension

Answer 20

is a measure of how hard it is to break the surface of a liquid. Related to Cohesion

Question 21

Moderation of temperature by water

Answer 21

Water can absorb or release a large amount of heat with only a slight change in its own temperature.

Question 22

Kinetic energy

Answer 22

The energy of motion

Question 23

Heat

Answer 23

a measure of the total amount of kinetic energy due to molecular motion.

Question 24

Temperature

Answer 24

measures the intensity of heat due to the average kinetic energy of molecules

Question 25

Calorie (cal)

Answer 25

the amout of heat required to raise the temperature of 1 g of water by 1 degree C

Question 26

Kilocalories (kcal)

Answer 26

the “calories” on food packages. 1 Kcal = 1,000 cal

Question 27

Specific heat

Answer 27

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

Question 28

Specific heat of water

Answer 28

1cal/g/ degree C

Question 29

Why does water resist changing its own temperature?

Answer 29

Water has high specific heat

Question 30

Evaporation

Answer 30

transformation of a substance from liquid to gas

Question 31

Heat of vaporization

Answer 31

the heat a liquid must absorb for 1 g to be converted to gas

Question 32

Evaporative cooling

Answer 32

As a liquid evaporate, its remaining surface cools. This is what helps stabilize temperatures in organisms and bodies of water