AnswersLA-Chemistry AElements, Compounds, and Mixtures

The Modern Atomic Theory Answers

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1
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The modern-day quantum model of the atom is better than John Dalton’s model because it

A
has set electron orbits.
B
has positive and negative particles in the nucleus.
C
can be represented in one dimension.
D
answers many questions about atoms.
2
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Natalie observes these characteristics in the model of an atom.(i) includes positive charge(ii) contains electrons(iii) explains the photoelectric effect(iv) suggests the probable location of electronsWhich model is Natalie most likely examining?

A
Bohr model
B
Dalton’s model
C
plum pudding model
D
electron-cloud model
3

The Bohr model of the atom explained why emission spectra are discrete. It could also be used to explain the photoelectric effect. Which is a correct explanation of the photoelectric effect according to the model?

A
Electrons are emitted with more speed when brighter light strikes them.
B
Electrons need small amounts of energy to be released from an atom.
C
Electrons move between levels only if they are hit by the right frequency of light.
D
Electrons need specific amounts of energy to jump levels and be emitted.
4

Which statement about Niels Bohr’s atomic model is true?

A
Higher orbits have lower energies.
B
Each orbit has a specific energy level.
C
Electrons can exist in any energy level.
D
Orbits close to the nucleus have no energy.
5

According to the Bohr model of an atom, what happens when an electron moves from the second energy level to the third energy level and then back to the second energy level?

A
Energy is absorbed and then stored in the atom.
B
Energy is released and then absorbed to form an absorption line.
C
Energy is absorbed and then released to form an emission line.
D
Energy is released from the atom, and the outer level is weakened.
6

Which statement describes a major drawback of the Bohr model that caused scientists to replace it?

A
It worked only for helium and larger atoms.
B
It did not identify the distance between an electron and the nucleus.
C
It contradicted the Heisenberg uncertainty principle.
D
It stated that spectral lines of atoms are similar.
7

Which atomic model states that it is impossible to know the exact location of electrons around the nucleus?

A
Bohr model
B
Dalton model
C
plum pudding model
D
electron-cloud model
8

How does the electron-cloud model describe electrons?

A
The exact position of an electron can be known.
B
An electron can be found at certain distances from the nucleus.
C
An electron has a high probability of being in certain regions.
D
Each electron follows a specific path around the nucleus.
9

Which equation was used by Albert Einstein to explain the photoelectric effect? [E = energy, h = Planck’s constant, and v = frequency.]

A
E =
Option A
B
E = hv
C
E =
Option C
D
E = h - v
10

Light of a certain energy shines on a metal and causes electrons to be emitted. Based on the research of Albert Einstein, what change would most likely result in stopping the emission of electrons from this metal?

A
an increase in the intensity of the light
B
a decrease in the intensity of the light
C
the use of light that has a higher frequency
D
the use of light that has a lower frequency

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The Modern Atomic Theory Answers — LA-Chemistry A