AnswersPhysical ScienceAtoms and the Periodic Table

Practice Test Answers

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1
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What is an atomic nucleus?

A
the central part of an atom, composed of protons and neutrons
B
the central part of an atom, composed of protons and electrons
C
the outer part of an atom in which neutrons move
D
the outer part of an atom in which electrons move
2
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Which describes radioactive decay of a substance?

A
Isotopes are the least stable during the later half-lives.
B
Isotopes are the most stable during the first half-life.
C
More of the radioactivity is lost during the first half-life than in later half-lives.
D
More of the radioactivity is lost during the fourth half-life than in the first half-life.
3

Atoms of two different elements must have different

A
electrical charges.
B
energy levels.
C
numbers of neutrons.
D
atomic numbers.
4

The atomic number of beryllium Be is 4 , and the atomic number of barium Ba is 56 Which comparison is best supported by this information?

A
They are in the same group because they have similar atomic masses, but they are in different periods because they have different chemical properties.
B
They are in the same group because they have similar atomic masses, but they are in different periods because they have very different atomic numbers.
C
They are in the same group because their atomic numbers are each multiples of four, but they are in different periods because they have different chemical properties.
D
They are in the same group because they have similar chemical properties, but they are in different periods because they have very different atomic numbers.
5

Which element is most likely to carry electric current easily?

A
selenium Se
B
tin Sn
C
sulfur cap s
D
antimony Sb
7

Which radioactive isotopes did the Curies discover?

A
polonium and radium
B
uranium and polonium
C
carbon-14 and uranium
D
radium and carbon-14
8

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
Most nonmetals are gaseous, but some are liquid or solid.
C
All nonmetals are solid unless they bond with a metal.
D
Most nonmetals are solids, but some are gaseous or liquid.
9

Who was the first chemist to organize elements by atomic number?

A
John Newlands
B
Henry Moseley
C
Antoine Lavoisier
D
Johann Wolfgang Döbereiner
10

Isra is analyzing the properties of several samples of elements to find out which sample is a metalloid. Which set of properties most likely belongs only to a metalloid?

A
is a gas and has low electrical conductivity
B
is brittle and forms acidic compounds
C
has a high luster and is very brittle
D
forms basic compounds and is a solid
13

Particle A has very little mass in comparison to Particle B. Both particles are in the same atom. Which is the best conclusion about Particles A and B?

A
Particle A has a positive charge, and Particle B is neutral.
B
Particle A orbits the nucleus, and Particle B is located in the nucleus.
C
They are located in the nucleus together.
D
They have the same charge.
15

What experimental evidence led to the development of this atomic model from the one before it?

A
A few of the positive particles aimed at a gold foil seemed to bounce back off of the thin metallic foil.
B
Equations were used to identify regions around the nucleus where electrons would likely be.
C
Experiments with water vapor showed that elements combine in specific proportions.
D
Cathode rays were bent in the same way whenever a magnet was brought near them.
16

What surprising result is explained using this model?

A
Most positive particles passed through because they were attracted by the small particles moving around the center.
B
A few positive particles bounced back because they bounced off of the net formed by the ovals.
C
Most positive particles passed through because of the empty space between the outer edge and the center.
D
A few positive particles bounced back because they were pushed away from the positive center.

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