Atomic Theory — Quiz Answers

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The plum pudding model of the atom states that

A
an atom is made up of electrons in a sea of positive charges.
B
each atom has a dense, positively charged center.
C
each atom has an overall negative charge.
D
an atom is a solid, indivisible sphere that makes up all matter.
3

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

A
An atom can join with other kinds of atoms.
B
An atom has a massive, positive center.
C
An atom is made up of smaller particles.
D
An atom is a round, solid mass.
5

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 examine a beam of charged particles
B
to change the strength of a proton within an atom
C
to speed up the flow of current flowing through a wire
D
to magnetize different atoms within a space
6

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

A
His results gave the first clues that atoms could be created and destroyed.
B
His results gave people a picture of what atoms look like for the first time.
C
His results gave the first evidence that atoms were made up of smaller particles.
D
His results gave the first experimental evidence that matter is made up of atoms.
7

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
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.
B
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.
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
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.
8

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 the orbits of atoms.
C
Some particles traveled through empty parts of the atom and some particles were deflected by electrons.
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.
9

The charged particles in the beams that Thomson studied came from atoms. As these particles moved away from their original atoms, they formed a visible beam. The current model of the atom includes protons, neutrons, and electrons. What is the best use of an atomic model to explain the charge of the particles in Thomson’s beams?

A
An atom’s negative particles are surrounded by positive matter, so the positive particles are easier to remove.
B
An atom’s larger positive particles are at a distance from the central negative particles, so the positive particles are easier to remove.
C
An atom’s positive particles are surrounded by negative matter, so the negative particles are easier to remove.
D
An atom’s smaller negative particles are at a distance from the central positive particles, so the negative particles are easier to remove.

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Atomic Theory — Quiz Answers — Physical Science