chapter11

Question 1

Are most of the atoms around us younger or older than the Sun?

Answer 1

most are older than the sun

Question 2

Why can’t atoms be seen with a powerful optical microscope?

Answer 2

Atoms are much smaller than a wavelength of light

Question 3

Why can atoms be seen with an electron beam?

Answer 3

The wavelength of the electrons is smaller than an atom

Question 4

What are the five most common elements in humans?

Answer 4

C, H, O, N, CA

Question 5

How are most of the elements with nuclei heavier than those of hydrogen and helium formed?

Answer 5

nuclear fusion in stars

Question 6

What is the most abundant element in the known universe?

Answer 6

hydrogen

Question 7

What element has the lightest atoms?

Answer 7

hydrogen

Question 8

Since atoms are mostly empty space, why don’t we fall through a floor we stand on?

Answer 8

Electrons in one atom repel the electrons in another.

Question 9

How does the electric charge of a proton compare with the electric charge of an electron?

Answer 9

it is equal and opposite

Question 10

What is meant by the term nucleon?

Answer 10

a proton or neutron

Question 11

Where in the atom is most of its mass concentrated? What is this mass composed of?

Answer 11

in the nucleus as protons and neutrons

Question 12

Which of the following are negatively charged?

Answer 12

electrons

Question 13

What does the atomic number of an element tell you about the element?

Answer 13

the number of protons in its nucleus

Question 14

How does one isotope differ from another?

Answer 14

has a different number of neutrons

Question 15

Distinguish between mass number and atomic mass.

Answer 15

Mass number is the number of nucleons; atomic mass is the total mass of an atom

Question 16

What is a mixture? Cite two examples

Answer 16

Atoms pressed together without bonding: air and salt and sand

Question 17

Compared with the energy it takes to separate oxygen and hydrogen from water, how much energy is released when they recombine?

Answer 17

The same amount of energy is released when they recombine.

Question 18

Which of these atoms has the largest number of neutrons in the nucleus?

Answer 18

gold

Question 19

What is the evidence that dark matter exists?

Answer 19

Gravitational forces within galaxies are too great to be accounted for with ordinary matter.

Question 20

What occurs when a proton and an antiproton meet?

Answer 20

They annihilate each other

Question 21

Dark matter is considered to be __________.

Answer 21

plentiful in the universe

Question 22

The charge in the nucleus of an antimatter hydrogen atoms is __________.

Answer 22

negative

Question 23

The number of atoms in a common water molecule is __________.

Answer 23

three

Question 24

Compared to the atoms that make up the body of an elderly person, the atoms that make up the body of a newborn baby are

Answer 24

the same age

Question 25

A granite block is mostly empty space because the atoms in the granite are

Answer 25

mostly empty space themselves

Question 26

Assuming all the atoms exhaled by Julius Caesar in his last dying breath are still in the atmosphere, we breathe in at least one of them each

Answer 26

single breath

Question 27

Which of the following statements is true?

Answer 27

there are only about 100 different kinds of atoms that combine to form all substances

Question 28

The difficulty of taking a photograph of an atom with light is

Answer 28

both of these

Question 29

If we doubled the magnifying power of the most powerful optical microscope in the world, we would

Answer 29

still not be able to see or photograph an atom.

Question 30

Atoms heavier than helium were at one time manufactured by

Answer 30

thermonuclear fusion

Question 31

Which of the following are electrically neutral?

Answer 31

neutrons

Question 32

An element is distinct because of its number of

Answer 32

protons

Question 33

Which is the smallest particle?

Answer 33

quark

Question 34

Although solid matter is mostly empty space, we don't fall through the floor because

Answer 34

of electrical forces

Question 35

A force that determines the chemical properties of an atom is

Answer 35

electrical force

Question 36

Atomic number refers to the number of

Answer 36

protons in the nucleus

Question 37

The number of protons in a neutral atom is balanced by an equal number of

Answer 37

orbital electrons

Question 38

Which of these has the greatest number of protons in its nucleus?

Answer 38

lead

Question 39

Which of these atoms has the greatest number of electrons?

Answer 39

uranium

Question 40

A pair of helium nuclei fused together produces

Answer 40

beryllium

Question 41

The chemical properties of matter are due mostly to their

Answer 41

electrons

Question 42

Compared to the mass of a hydrogen atom, the mass of an oxygen atom is

Answer 42

16x as great

Question 43

How many protons should be added to the nuclei of oxygen atoms so the resulting gas will glow red when an electric current is in it?

Answer 43

2

Question 44

Heavy atoms are not appreciably larger in size than light atoms because the nuclei of heavy atoms have more

Answer 44

electric charge

Question 45

An isotope is simply an atom that

Answer 45

has different numbers of neutrons for the same element.

Question 46

A nucleon has a mass of about

Answer 46

both are the same

Question 47

Which of the following is NOT a compound?

Answer 47

air

Question 48

Which of the following is NOT a mixture?

Answer 48

none

Question 49

Which of the following statements is true?

Answer 49

molecules are the smallest subdivision of matter that still retain a substance's chemical properties

Question 50

When carbon and oxygen atoms combine, energy is

Answer 50

released by the reaction

Question 51

How many atoms are in this carbohydrate molecule, C6H12O6?

Answer 51

24

Question 52

If a gram of antimatter meets a kilogram of matter, the amount of mass to survive is

Answer 52

999 grams

Question 53

If no molecules in a body could escape, would the body have any odor?

Answer 53

no

Question 54

What element results if two protons and two neutrons are ejected from a radium nucleus?

Answer 54

radon

Question 55

To become a negative ion, does an atom lose or gain an electron?

Answer 55

gains

Question 56

To become a positive ion, does an atom lose or gain an electron?

Answer 56

loses

Question 57

The electrical force is stronger between the nucleus and an inner electron for atoms of

Answer 57

high atomic number

Question 58

Mass number refers to the number of

Answer 58

nucleons in the nucleus

Question 59

What is the molecular mass of a water molecule?

Answer 59

18 amu

Question 60

The mass of matter is due mostly to its

Answer 60

protons

Question 61

The volume of matter is due mostly to its

Answer 61

electrons

Question 62

Which of these atoms has the greatest amount of electrical charge in its nucleus?

Answer 62

uranium

Question 63

What causes dust particles and tiny grains of soot to move with Brownian motion?

Answer 63

collisions with invisible molecules

Question 64

Who first explained Brownian motion and made a convincing case for the existence of atoms?

Answer 64

albert einstein

Question 65

Which of the following is an inert gas?

Answer 65

helium

Question 66

How many different kinds of elements are in a water molecule?

Answer 66

two