Download HW: Atomic Structure Practice

Atomic Structure Practice
Name:
1.
Which one of the following correctly gives the number of electrons, protons and neutrons in a neutral
atom of the nuclide
A.
B.
C.
D.
65
29 Cu
?
Number of electrons
65
36
29
29
Number of protons
29
36
29
29
Number of neutrons
36
29
65
36
(1)
2.
In the Geiger-Marsden experiment, α particles are scattered by gold nuclei. The experimental results
indicate that most α particles are
A.
scattered only at small angles.
B.
scattered only at large angles.
C.
absorbed in the target.
D.
scattered back along the original direction.
(1)
3.
Which one of the following provides direct evidence for the existence of discrete energy levels in an
atom?
A.
The continuous spectrum of the light emitted by a white-hot metal.
B.
The line emission spectrum of a gas at low pressure.
C.
The emission of gamma radiation from radioactive atoms.
D.
The ionization of gas atoms when bombarded by alpha particles.
4.
Isotopes provide evidence for the existence of
A.
protons.
B.
electrons.
C.
nuclei.
D.
neutrons.
(1)
(1)
5.
Which one of the following correctly identifies the atomic (proton) number and mass (nucleon) number
of a nucleus that has neutrons n and protons p?
Atomic number
Mass number
A.
p
n
B.
p
n+p
C.
n
p
D.
n+p
p
(1)
6.
Ag-102, Ag-103 and Ag-104 are three isotopes of the element silver.
Which one of the following is a true statement about the nuclei of these isotopes?
A.
All have the same mass.
B.
All have the same number of nucleons.
C.
All have the same number of neutrons.
D.
All have the same number of protons.
7.
The number of nucleons in a nucleus is the number of
A.
particles in the nucleus.
B.
neutrons in the nucleus.
C.
protons in the nucleus.
D.
protons plus neutrons in the nucleus.
8.
The emission and absorption spectra of different elements provides evidence for the existence of
A.
isotopes.
B.
neutrons.
C.
protons.
D.
atomic energy levels.
(1)
(1)
(1)
1
9.
Which of the following gives the correct number of protons and number of neutrons in the nucleus of
11
B?
5
A.
B.
C.
D.
Number of protons
5
5
6
11
Number of neutrons
6
11
5
5
(1)
10.
Which one of the following provides evidence for a nuclear model of the atom?
A.
Natural radioactive decay
B.
The ionizing properties of radiation
C.
The stability of certain elements
D.
The scattering of alpha particles by gold foil
11.
Which of the following identifies the significant interaction(s) between nucleons inside the nucleus?
A.
Nuclear only
B.
Coulomb only
C.
Nuclear and Coulomb
D.
Gravitational, nuclear and Coulomb
12.
Which one of the following correctly identifies the mass and momentum of a photon?
Mass
Momentum
A.
zero
zero
B.
zero
non-zero
C.
non-zero
zero
D.
non-zero
non-zero
(1)
(1)
(1)
13.
The diagram below shows the path followed by an alpha-particle in the vicinity of the nucleus of a gold
atom.
alpha-particle
nucleus
Which of the following is correct for the alpha-particle?
A.
The force acting on it changes direction.
B.
The force acting on it is smaller than that acting on the nucleus.
C.
Its potential energy is constant.
D.
Its kinetic energy is constant.
(1)
14.
This question is about atomic spectra.
–15
–15
J to an energy level of
J. Determine the wavelength of the emitted photon.
(Total 3 marks)
15.
This question is about atomic and nuclear structure.
In a nuclear model of the atom, most of the atom is regarded as empty space. A tiny nucleus is surrounded
by a number of electrons.
(a)
Outline one piece of experimental evidence that supports this nuclear model of the atom.
(3)
(b)
Explain why the protons in a nucleus do not fly apart from each other.
(2)
2
(c)
29
In total, there are approximately 10 electrons in the atoms making up a person.
(i)
Estimate the electrostatic force of repulsion between two people standing 100 m apart as a
result of these electrons.
(4)
(ii)
Explain why two people standing 100 m apart would not feel the force that you have
calculated in part (i).
(2)
(Total 11 marks)
16.
This question is about energy levels and atomic models.
(a)
Diagram 1 below shows some of the energy levels (measured in electron-volts) of the hydrogen
atom. Diagram 2 is a representation of part of the visible spectrum of atomic hydrogen (not to
scale).
Diagram 1
0
–0.54
–0.85
Diagram 2
–1.5
= 660nm
= 470nm
= 430nm
–3.4
energy / eV
red
blue
violet
–13.6
(i)
State the value of the ionization energy of hydrogen.
(1)
(ii)
The wavelength corresponding to the red line in the visible spectrum of atomic hydrogen is
660 nm. Deduce that the energy of a photon of wavelength 660 nm is 1.9 eV.
(3)
(iii)
On diagram 1, draw an arrow to show the electron transition between energy levels that
gives rise to a photon of energy 1.9 eV. Label this arrow with the letter R.
(1)
(iv)
On diagram 1 and using your answer to (iii), draw arrows to show the electron transitions
that give rise to the blue line and to the violet line in the visible spectrum of atomic
hydrogen. Label these arrows B and V respectively.
(1)
(b)
The kinetic energy of an electron in the ground state of a hydrogen atom is 13.6 eV. Deduce that
an electron in the ground state of the hydrogen atom has a de Broglie wavelength of approximately
–10
–31
3.3
kg).
(4)
(Total 13 marks)
3