Mastering Biology Chapter 2 Test Bank (62)

Front 1

Every atom except ________ has one or more neutrons in its nucleus.

Back 1

hydrogen

Front 2

The sum of the atomic weights in any given molecule is called its ________.

Back 2

mass

Front 3

The nutritionist's Calorie, which biologists call a kilocalorie, is the equivalent of

________ heat-energy calories.

Back 3

1,000

Front 4

The water strider skates along the surface of water due to a property of liquids called

________.

Back 4

surface tension

Front 5

The attraction between a slight positive charge on a hydrogen atom and the slight

negative charge of a nearby atom is a ________.

Back 5

hydrogen bond

Front 6

1.0 M solution of HCl has a pH of

Back 6

1

Front 7

The part of the atom of greatest biological interest is the

Back 7

electron

Front 8

Hydrogen, deuterium, and tritium all possess the same

Back 8

number of protons & atomic #

Front 9

Which component of an atom does not significantly influence mass?

Back 9

electrons

Front 10

Which of the following describes an unusual property of water?

A) Three different physical phases

B) A solid state that is less dense than its

liquid state

C) Heat loss when changing from a liquid to a gas

D) Limited ionization

Back 10

A solid state that is less dense than its liquid state.

Front 11

The number of protons in an uncharged atom equals the number of

Back 11

electrons

Front 12

Because atoms can have the same number of protons but a different number of neutrons,

elements have

Back 12

isotopes

Front 13

An element has a mass weight of 131.3. The reason the number includes 0.3 is because

Back 13

atomic weight is the average of the mass of all its isotopes.

Front 14

The atomic number of an element is the same as the number of

Back 14

protons in each atom

Front 15

The mass number of an element is the same as the number of

Back 15

protons + neutrons in each atom

Front 16

All except __________ abide by the octet rule.

Back 16

hydrogen

Front 17

In a hydrogen molecule, the two atoms are held together by

Back 17

a shared pair of electrons

Front 18

Hydrogen bonds

Back 18

form between different molecules

Front 19

What determines if a molecule is polar, nonpolar, or ionic?

Back 19

The differences in the electronegativities of the atoms

Front 20

The number of different elements that exist is closest to

A) 12.

B) 24.

C) 48.

D) 96.

E) 192.

Back 20

96

Front 21

Which of the following elements is the most chemically reactive?

Back 21

hydrogen

Front 22

A single covalent chemical bond represents the sharing of how many electrons?

Back 22

2

Front 23

The molecular weight of water is 18.0154. One mole of water weighs __________ grams.

Back 23

18

Front 24

Ionic bonds are

Back 24

attractions between oppositely charged ions

Front 25

What is the difference between covalent and ionic bonds?

Back 25

covalent bonds are the sharing of electrons between atoms, and ionic bonds are the transfer of electrons from one atom to the other.

Front 26

Which contains more molecules, a mole of hydrogen or a mole of carbon?

Back 26

Carbon

Front 27

Sweating is a useful cooling device for humans because

Back 27

water takes up a great deal of heat in changing from its liquid state to its gaseous

Front 28

To maintain a normal body temperature when exposed to extreme heat, __________ is

used to absorb excess calories of heat.

Back 28

evaporation

Front 29

What two characteristics make water different from most other compounds?

Back 29

Its solid state is less dense than its liquid state, and it takes up large amounts of heat

to change to its gaseous state

Front 30

Which characteristic of water contributes to the relatively constant temperatures of the

oceans?

Back 30

It takes a large amount of heat energy to raise the temperature of water.

Front 31

Ice floats because

Back 31

the crystal takes up more space than the liquid.

Front 32

Ice is used in beverages because

Back 32

it absorbs a lot of heat when it melts.

Front 33

If you place a paper towel in a dish of water, the water will move up the towel by capillary action. What property of water gives rise to capillary action?

Back 33

Water can form hydrogen bonds.

Front 34

An alkaline solution contains

Back 34

more OH- ions than H+ ions.

Front 35

The pH 6.0 contains

Back 35

10-6 moles of hydrogen ions.

Front 36

Solutions that contain buffers tend to resist pH changes because buffers

Back 36

change from non-ionic to ionic in response to changes in pH and release or absorb

H+.

Front 37

What is the difference between an acid and a base?

Back 37

An acid releases H+ ions in solution, while a base accepts H+ ions.

Front 38

All except which of the following is nonpolar?

A) O2 B) N2 C) CH4 D) NaCl E) H2

Back 38

NaCl

Front 39

Polar molecules

Back 39

have an unequal distribution of electric charge.

Front 40

A drop of oil in water disperses when detergent is added because

Back 40

the nonpolar parts of the detergent molecules associate with the oil and the polar

parts of the detergent molecules associate with the water.

Front 41

When potassium hydroxide (KOH) is added to water, it ionizes, releasing hydroxide ions.

This solution is

Back 41

Basic

Front 42

H2SO4 can ionize to yield two H+ ions and one SO4 2ñ ion. H2SO4 is

Back 42

An Acid

Front 43

Acid rain is a serious environmental problem. A sample of rainwater collected in the Adirondack Mountains had an H+ concentration of 10-4 mol/L. The pH of this sample

Back 43

4

Front 44

Cholesterol is composed primarily of carbon and hydrogen atoms. What property would

you expect cholesterol to have?

Back 44

It's insoluble in water

Front 45

Butane and isobutane have the same chemical formula but different arrangements of

atoms. These two compounds are called

Back 45

isomers

Front 46

One dalton is the same as the mass of one

Back 46

proton

Front 47

Two carbon atoms held together in a double covalent bond share __________ electron(s).

Back 47

4

Front 48

Particles having a net negative charge are called

Back 48

anions

Front 49

Avogadro's number is the number of

Back 49

molecules in a mole

Front 50

a mole is

Back 50

6.02 X 1023 molecules.

Front 51

To determine the number of molecules in a teaspoon of sugar you need

Back 51

the weight and molecular weight of the sugar, and Avogadro's number.

Front 52

How would you make 100 ml of an aqueous solution with a 0.25 M concentration of a

compound that has a molecular weight of 200 daltons?

Back 52

Take 5 grams of the compound and add water until the volume equals 100 ml.

Front 53

The hydrogen bond between two water molecules arises because water is

Back 53

polar

Front 54

The functional group written as -COOH is called the __________ group.

Back 54

carboxyl

Front 55

An atom that is neutrally charged contains

Back 55

the same number of positive particles as negative particles.

Front 56

The four elements most common in organisms are

Back 56

carbon, oxygen, hydrogen, and nitrogen.

Front 57

Select the statement that describes a difference between ionic bonds and covalent bonds.

A) An ionic bond is stronger.

B) Electron sharing is more equal in the covalant bond.

C) An ionic bond occurs more often in aqueous solutions.

D) An ionic bond occurs only in acids.

E) A covalent bond occurs in nonpolar molecules.

Back 57

Electron sharing is more equal in the covalant bond.

Front 58

Which of the following statements about the number of bonds formed by atoms is true? A) Oxygen forms one, carbon forms four, and hydrogen forms one.

B) Oxygen forms four, carbon forms four, and hydrogen forms four.

C) Oxygen forms two, carbon forms four, and hydrogen forms none.

D) Oxygen forms two, carbon forms four, and hydrogen forms one.

E) Oxygen forms two, carbon forms two, and hydrogen forms two.

Back 58

Oxygen forms two, carbon forms four, and hydrogen forms one.

Front 59

Of the following types of molecules, the one always containing nitrogen is

A) thiol.

B) sugar.

C) hydrocarbon.

D) alcohol.

E) amino acid.

Back 59

E) amino acid.

Front 60

A typical distance between two atoms held together by a covalent bond is

Back 60

0.2 nanometer.

Front 61

Surface tension and capillary action occur in water because it

Back 61

has hydrogen bonds.

Front 62

Which pair has similar chemical properties? A) 1H and 22Na

B) 12C and 28Si

C) 16O and 8S

D) 12C and 14C

E) 8H and 2He

Back 62

12C and 14C