Answers2003350 Chemistry HONORS Sem 1 - MarezThe Modern Atomic Theory

The Modern Atomic Theory — Unit test Answers

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An electron in a hydrogen atom moves from level 3 to level 1. In a second hydrogen atom, an electron drops from level 2 to level 1. Which statement describes the most likely result?

A
The first atom emits light with more energy.
B
The second atom emits light with more energy.
C
The first and second atoms absorb energy without emitting light.
D
The first and second atoms emit light with the same amount of energy.
2
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Which is a component of John Dalton’s atomic theory?

A
The ratio of atoms in a compound can vary.
B
The atoms of a single element differ.
C
An atom is a small particle that cannot be broken down.
D
Atoms of different elements can be identical.
3

The table below gives the data that is needed to calculate the average atomic mass of element B.IsotopeAtomic mass (amu)Relative abundance (%)B-1010.0119.91B-1111.0180.09Based on these data, what is the average atomic mass of element B?

A
10.01
B
10.51
C
10.81
D
11.01
4

Which is a correct comparison between the modern quantum model and John Dalton’s model of the atom?

A
The modern model is not as widely accepted by scientists as Dalton’s model.
B
The modern model states that atoms of all elements are identical, whereas Dalton’s model does not.
C
The modern model recognizes particles in the atom, whereas Dalton’s model does not.
D
The modern model does not explain emission spectra, whereas Dalton’s model does.
5

Which statement best describes the light that will cause emission of electrons from a given metal through the photoelectric effect?

A
light with a low enough intensity
B
light with a high enough frequency
C
light with a high enough intensity
D
light with a low enough frequency
6

How are isotopes defined?

A
forms of different elements that have the same number of neutrons in each atom
B
forms of different elements that have the same number of protons in each atom
C
forms of the same element that differ in the number of neutrons in each atom
D
forms of the same element that differ in the number of protons in each atom
7

To explain the photoelectric effect, Albert Einstein linked the photoelectric effect to an idea from which scientist?

A
Heinrich Hertz
B
Isaac Newton
C
Max Planck
D
Thomas Young
8

Which scientist’s law about the ratios of masses of elements in a compound did John Dalton’s work on the atomic structure help to explain?

A
Democritus
B
J. J. Thomson
C
Ernest Rutherford
D
Joseph Proust
9

The mass number of a chromium atom is 52 and it has 24 protons. How many neutrons does this atom have?

A
24
B
28
C
76
D
80
10

What did J. J. Thomson observe when he applied electric voltage to a cathode ray tube in his famous experiment?

A
The stream of cathode ray particles was moving very slowly.
B
The glass opposite of the negative electrode started to glow.
C
The electric voltage had little effect on the stream of particles.
D
The tube contained two pieces of metal that served as electrodes.
11

Which diagram best illustrates the atomic model that Rutherford derived from his gold foil experiment?

A
A small orange circle with seven plus signs is at the center of a larger dotted circle. Between the two circles are 7 small green circles, each labeled with a negative sign.
Option A
B
A red circle with a large, faint plus sign visible contains 10 small orange circles labeled with minus signs.
Option B
C
An orange circle bounded by a heavier, darker orange line surrounds the word Atom.
Option C
D
A small blue circle labeled with a minus sign lies at the center of a larger circle. Spaced around the outer circle are three small green circles labeled with plus signs.
Option D
12

Which of these properties is the best one to use for identification of an element?

A
the number of neutrons in the atomic nucleus
B
the number of protons in the atomic nucleus
C
the number of isotopes that are formed by the element
D
the number of charges on ions of the element

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