N/A — Exam Answers

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An atom of carbon cap c forms covalent bonds with two atoms of oxygen cap o to form carbon dioxide. How are the valence electrons of these atoms rearranged to form the bonds?

A
Many valence electrons are shared between the atoms.
B
Electrons are transferred from the carbon atom to the oxygen atoms.
C
A few valence electrons are shared between the atoms.
D
Electrons are transferred from the oxygen atoms to the carbon atoms.
24

Which is the balanced equation for cap s sub 8 plus cap o sub 2 rightarrow SO sub 2 ?

A
cap s sub 8 plus cap o sub 2 rightarrow cap s sub 8 cap o sub 2
B
cap s sub 8 plus cap o sub 16 rightarrow 8 SO sub 2
C
cap s sub 8 plus cap o sub 2 rightarrow cap s sub 8 plus cap o sub 2
D
cap s sub 8 plus 8 cap o sub 2 rightarrow 8 SO sub 2
25

Which is an example of a chemical change?

A
chopping onions
B
frying an egg
C
melting butter
D
boiling water
27

Which describes a value for density?

A
a value for mass, such as kg , divided by a value for volume, such as m cubed
B
a value for time, such as s , divided by a value for distance, such as m
C
a value for volume, such as m cubed , divided by a value for mass, such as kg
D
a value for distance, such as m , divided by a value for time, such as s
28

How long will a radioactive isotope decay?

A
until it becomes a different, stable element
B
until it reaches its half-life
C
until the neutrons are returned to the base element level
D
until there is no more material
31

Why do nuclear power plants use fission instead of fusion?

A
The energy from fusion cannot yet be converted to electricity.
B
Per gram of fuel, fission releases more energy than fusion.
C
Fusion requires conditions that use too much energy to maintain.
D
Scientists have not yet gotten a fusion reaction to happen on Earth.
32

According to the electron sea theory, what happens when a collection of metal atoms are in close proximity to each other?

A
Some electrons float amongst the atoms.
B
Some protons float amongst the atoms.
C
All protons become free and separate from nuclei.
D
All electrons become free and separate from nuclei.
33

Covalent bonds tend to make atoms more stable by helping them

A
empty out their innermost electron shell.
B
empty out their outermost electron shell.
C
fill up their innermost electron shell.
D
fill up their outermost electron shell.
35

A miner develops cancer of the esophagus. Ten years before, he had been exposed to radiation when he worked for a year in a mine. He had also smoked cigarettes for a number of years, but had quit five years ago. Which statement best describes the miner’s condition?

A
Cancer caused by exposure at the mine would have appeared while he was at the mine, so smoking is the more likely cause.
B
The cancer is likely the result of natural exposure to radiation in the environment and not related to either the mine or smoking.
C
Tests can determine whether the cancer was caused by exposure at the mine or by compounds in cigarette smoke so that a treatment can be determined.
D
It is unlikely that a specific cause can be determined, but the treatment would likely be the same in either case.
36

Which statement best explains how the mass of an atom is organized?

A
The mass is spread evenly throughout the whole atom.
B
Most of the mass is contained in the electron cloud.
C
The mass is spread evenly throughout the electron cloud.
D
Most of the mass is contained in the nucleus.
38

Which is true of transition metals when moving from left to right on the periodic table?

A
Atomic radii decrease slightly and then start to increase.
B
Atomic radii increase slightly and then start to decrease.
C
The cation radii become larger across the period.
D
The d sublevels are not filled across the period.
40

Which synthetic and natural polymers can be used to make thread or rope?

A
vulcanized rubber and nylon
B
vulcanized rubber and starch
C
starch and cellulose
D
nylon and cellulose

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