Chp 2

Question 1

Surface Tension

Answer 1

a measure of how difficult it is to stretch or break the surface of a liquid

Question 2

Heat Vaporization

Answer 2

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

Question 3

Adhesion

Answer 3

the clinging of one substance to another

Question 4

Evaporative cooling

Answer 4

the cooling of a liquid’s surface as some of the liquid evaporates

Question 5

Ionic bonds form as a result of

Answer 5

the attraction between ions that have opposite charges.

Question 6

Equal Sharing of electrons occurs in a

Answer 6

Covalent bond

Question 7

Unequal sharing of electrons occurs in a

Answer 7

polar covalent bond

Question 8

A hydrogen bond is formed as a result of

Answer 8

the noncovalent attraction between a hydrogen atom and an atom with a partial negative charge.

Question 9

Van der Waals interactions involve

Answer 9

chance accumulations of electrons as they move around atomic nuclei.

Question 10

A molecule consisting of two atoms, such as hydrogen gas (H2) or oxygen (O2) is

Answer 10

always linear

Question 11

Molecules containing many carbon atoms, such as glucose (C6H12O6)

Answer 11

have more complex shapes than that of a completed tetrahedron.

Question 12

Which main molecules have a tetrahedral shape

Answer 12

methane, CH4, ammonia, NH3, and water, H2O

Question 13

more carbon dioxide causes

Answer 13

an increase in carbonic acid (H2CO3),

Question 14

A covalent bond will be polar if

Answer 14

one of the atoms sharing electrons is more electronegative

Question 15

An acid is

Answer 15

a substance that donates hydrogen ions to a solution

Question 16

Bases

Answer 16

accept hydrogen ions. Bases thereby decrease the hydrogen ion concentration of solutions.

Question 17

Basic Solutions

Answer 17

have a pH between 7 and 14

Question 18

A buffer is a substance that

Answer 18

minimizes changes in the concentrations of H+ and OH− in a solution and therefore resists changes in pH. t does so by accepting hydrogen ions from the solution when they are in excess and donating hydrogen ions to the solution when they have been depleted.

Question 19

The chemical characteristics or reactivity of an element depend mostly on

Answer 19

the number of electrons in its outermost shell.

Question 20

When the number of protons and electrons possessed by an atom are unequal, the atom

Answer 20

is an ion

Question 21

An atom that normally has_______in its outer shell would not form chemical bonds with other atoms.

Answer 21

eight electrons

Question 22

Cells are surrounded by water, and cells themselves consist of about 70 to 95 percent water. As a result,

Answer 22

the temperature of living things tends to change relatively slowly

a variety of nutrient molecules is readily available as dissolved solutes

waste products produced by cell metabolism can be easily removed

dissolved substances can be easily transported within a cell or between cells in multicellular organisms

Question 23

Coastal climates are more moderate than inland climates primarily because of water’s high __________.

Answer 23

specific heat

Question 24

The tendency of water molecules to stay close to each other as a result of hydrogen bonding __________.

Answer 24

acts to moderate temperature

provides the surface tension that allows leaves to float on water

is called cohesion

keeps water moving through the vessels in a tree trunk

Question 25

Sweating has a cooling effect because of water’s high

Answer 25

heat of vaporization.

Question 26

Hydrophilic substances

Answer 26

have charges or partial charges to which water molecules can adhere

Question 27

A solution at pH 6 contains____than the same amount of solution at pH 8.

Answer 27

100 times more H+

Question 28

The amount of heat required to change the temperature of 1 g of a substance by 1°C is defined as .

Answer 28

the specific heat of that substance

Question 29

Adhesion is best described as .

Answer 29

the clinging of one substance to another substance