Practice Exam Answers

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1
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Atoms of two different elements must have different

A
atomic numbers.
B
energy levels.
C
electrical charges.
D
numbers of neutrons.
2
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Atoms of iron Fe form metallic bonds with other iron atoms. How are the valence electrons of these atoms rearranged to form the bonds?

A
Many valence electrons are shared between the atoms.
B
A few valence electrons are shared between the atoms.
C
Electrons are transferred to the iron atoms from atoms in the air.
D
Electrons are transferred from the iron atoms to atoms in the air.
3

Which is a pure substance?

A
nitrogen
B
air
C
tap water
D
apple juice
4

Which example illustrates a chemical change?

A
burning wood
B
smashing a soda can
C
shredding paper
D
chopping wood
5

What is produced during the replacement reaction of Cu open paren NO sub 3 close paren sub 2 and Zn ?

A
Zn plus Cu open paren NO sub 3 close paren sub 2
B
Zn open paren NO sub 3 close paren sub 2 plus Cu
C
ZnNO sub 3 plus Cu
D
ZnCu plus 2 NO sub 3
6

How does Rutherford’s model of the atom compare with Thomson’s model?

A
They both describe atoms as small, indivisible spheres.
B
They both describe electrons as being surrounded by the positive matter.
C
They both describe atoms as being made up of positive and negative matter.
D
They both describe electrons as moving around the nucleus.
8

While looking at bromine Br on the periodic table, a student needs to find another element with very similar chemical properties but with a different atomic mass. Which best describes the student’s options?

A
There are many possible elements, and they are all in the same vertical column as bromine.
B
There are two possible elements, and they are directly above and below bromine.
C
There are many possible elements, and they are all in the same horizontal row as bromine.
D
There are two possible elements, and they are directly to the left and right of bromine.
10

What best describes the states of nonmetals when they are at room temperature?

A
All nonmetals are gaseous unless they bond with a metal.
B
All nonmetals are solid unless they bond with a metal.
C
Most nonmetals are solids, but some are gaseous or liquid.
D
Most nonmetals are gaseous, but some are liquid or solid.
11

What is a limitation of using a chemical formula, such as cap c sub 6 cap h sub 12 cap o sub 6 , to represent a compound?

A
The chemical formula does not show the chemical symbols of the elements in the compound.
B
The chemical formula does not show the types of elements that make up the compound.
C
The chemical formula does not show how the atoms are connected to one another.
D
The chemical formula does not show the number of atoms of each element in a molecule.
12

Uranium is a type of atom. In special circumstances that usually involve high amounts of energy, uranium can be broken. When this occurs, different pieces of the original atom remain, including a substance called plutonium. Which statement most likely describes plutonium?

A
It must no longer be a form of matter.
B
It must be a different kind of atom.
C
It will be different than, but have the same properties as, uranium.
D
It will still be uranium, just smaller pieces of uranium.
15

When balanced, which equation would have the coefficient 3 in front of any of the reactants?

A
cap c sub 2 cap h sub 4 cap o sub 2 plus cap o sub 2 rightarrow CO sub 2 plus cap h sub 2 cap o
B
Zn plus HCl rightarrow ZnCl sub 2 plus cap h sub 2
C
Fe plus AgNO sub 3 rightarrow Fe open paren NO sub 3 close paren sub 2 plus Ag
D
cap h sub 2 SO sub 4 plus cap b OH sub 3 rightarrow cap b sub 2 open paren SO sub 4 close paren sub 3 plus cap h sub 2 cap o
16

Which ranks these materials by the attraction between their atoms from the weakest to the strongest?

A
solid iron ore, liquid honey, liquid water, oxygen gas
B
oxygen gas, liquid honey, liquid water, solid iron ore
C
liquid water, liquid honey, oxygen gas, solid iron ore
D
oxygen gas, liquid water, liquid honey, solid iron ore
17

The pH of a solution is 7 Which best describes the solution?

A
The solution has fewer hydrogen ions than hand soap.
B
The solution has the same number of hydrogen ions and hydroxide ions.
C
The solution has more hydrogen ions than hydroxide ions.
D
The solution has the same number of hydrogen ions as apple juice.
18

Chanel has some cotton candy that came in a cloudy shape. She wants to make it more dense. Which describes the candy before and after Chanel manipulated it?

A
The candy before was compacted, and the candy after was fluffy.
B
The candy before was a ball, and the candy after was a cube.
C
The candy before was a cube, and the candy after was a ball.
D
The candy before was fluffy, and the candy after was compacted.
19

Which describes how a centrifuge separates a mixture?

A
It heats a sample to separate based on density.
B
It heats a sample to separate based on boiling point.
C
It spins a sample to separate based on density.
D
It spins a sample to separate based on boiling point.
20

After a radioactive atom decays, it is the same element that it was before with no measurable change in mass. Which kind of decay has occurred, and how do you know?

A
alpha decay because it creates a new isotope of the same element
B
gamma decay because photons have no mass
C
alpha decay because alpha particles have no mass
D
beta decay because this kind of decay cannot change one element into another

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