AnswersNM-Physical Science AUnit Test

Atomic Theory Answers

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1
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Oppositely charged objects attract each other. This attraction holds electrons in atoms and holds atoms to one another in many compounds. However, Ernest Rutherford’s model of the atom failed to explain why electrons were not pulled into the atomic nucleus by this attraction.What change to the atomic model helped solve the problem seen in Rutherford’s model?

A
Bohr’s work with atomic spectra led him to say that the electrons were limited to existing in certain energy levels, like standing on the rungs of a ladder.
B
Bohr’s work with cathode rays led him to say that the electrons were located within the mass of positive material, like plums in a pudding.
C
Thomson’s work with cathode rays led him to say that the electrons were located within the mass of positive material, like plums in a pudding.
D
Thomson’s work with atomic spectra led him to say that the electrons were limited to existing in certain energy levels, like standing on the rungs of a ladder.
2
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Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below.

Question illustration
A
A few of the positive particles aimed at a gold foil seemed to bounce back.
B
The colors of light emitted from heated atoms had very specific energies.
C
Equations were used to identify regions around the nucleus where electrons would likely be.
D
Cathode rays were bent in the same way whenever a magnet was brought near them.
3

What new characteristic did John Dalton add to the model of the atom?

A
An atom is a round, solid mass.
B
An atom has a massive, positive center.
C
An atom is made up of smaller particles.
D
An atom can join with other kinds of atoms.
4

What did Bohr’s model of the atom include that Rutherford’s model did not have?

A
a nucleus
B
energy levels
C
electron clouds
D
smaller particles
5

The atomic models after Dalton’s time included ideas about the atomic structure.Which atomic model that shows the atomic structure is missing from this set?

Question illustration
A
Niels Bohr’s model
B
Schrödinger’s model
C
Rutherford’s model
D
Thomson’s model
6

Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below.

Question illustration
A
A few of the positive particles aimed at a gold foil seemed to bounce back.
B
The colors of light emitted from heated atoms had very specific energies.
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.
7

Rutherford tracked the motion of tiny, positively charged particles shot through a thin sheet of gold foil. Some particles traveled in a straight line and some were deflected at different angles.Which statement best describes what Rutherford concluded from the motion of the particles?

A
Some particles traveled through empty parts of the atoms and some particles were deflected by neutrons.
B
Some particles traveled through empty parts of the atom and some particles were deflected by electrons.
C
Some particles traveled through empty parts of the atom and some particles were deflected by the orbits of atoms.
D
Some particles traveled through empty parts of the atom and some particles were deflected by small areas of high-density positive charge in atoms.
8

A cathode ray tube is made of glass with a small amount of some kind of gas in it. It has metal electrodes at each end to pick up an electric current. The electrodes are named "positive” and "negative."What are one of the main uses of this device ?

A
to speed up the flow of current flowing through a wire
B
to examine a beam of charged particles
C
to magnetize different atoms within a space
D
to change the strength of a proton within an atom
9

Why did Thomson’s results from experimenting with cathode rays cause a big change in scientific thought about atoms?

A
His results gave people a picture of what atoms look like for the first time.
B
His results gave the first clues that atoms could be created and destroyed.
C
His results gave the first experimental evidence that matter is made up of atoms.
D
His results gave the first evidence that atoms were made up of smaller particles.
10

Which scientist developed the first model of the atom that proposed the structure of the inside of an atom?

A
Dalton
B
Bohr
C
Rutherford
D
Thomson

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Atomic Theory Answers — NM-Physical Science A