The Structure of the Atom
Practice Test
1.
How is the atomic mass unit
amu
defined?
a.
1/12 the mass of a carbon-12 atom
b.
1/14 the mass of a nitrogen-14 atom
c.
1/16 the mass of an oxygen-16 atom
d.
1/13 the mass of a carbon-13 atom
2.
Which of the following is not a fundamental particle in an atom?
SC.A.2.4.2
a.
electron
b.
neutron
c.
element
d.
proton
3.
What is the charge of an alpha particle?
SC.A.2.4.6
a.
1
+
b.
0
c.
1
–
d.
2
+
4.
What is the charge of a beta particle?
SC.A.2.4.6
a.
2
+
b.
1
–
c.
1
+
d.
0
5.
Which of the following is a correct statement about a neutral atom?
SC.A.2.4.1
a.
Neutrons are present in the nucleus.
b.
The atoms carry a positive or a negative charge.
c.
The atom has the same number of proton and electrons.
d.
The atom is radioactive.
6.
An atom of an element contains eight electrons. What is the identity of this element?
a.
carbon
b.
oxygen
c.
fluorine
d.
nitrogen
7.
Which of the following statements is correct?
SC.A.2.4.2
a.
A proton is about 2000 times more massive than an electron.
b.
The nucleus is mostly empty space.
c.
An electron is about 2000 times more massive than a proton.
d.
A neutron will always be found orbiting the nucleus.
8.
Which scientist determined that almost all of an atom’s mass of is located in its nucleus?
a.
Thomson
b.
Rutherford
c.
Democritus
d.
a. Dalton
9.
The atomic number of an element is defined by its number of ________.
a.
electrons
b.
neutrons
c.
nuclei
d.
protons
10.
What is the primary factor in determining an atom’s stability?
SC.A.2.4.3
a.
alpha particle to beta particle ratio
b.
neutron to electron ratio
c.
proton to electron ratio
d.
neutron to proton ratio
11.
What fundamental particle is identical to a beta particle?
SC.A.2.4.3
a.
the positron
b.
the proton
c.
the neutron
d.
the electron
12.
What is the negatively—charged particle in an atom?
SC.A.2.4.2
a.
neutron
b.
electron
c.
proton
d.
positron
13.
How do gamma rays differ from alpha particles and beta particles?
SC.A.2.4.3
a.
Alpha particle and beta particle emissions result in the formation of new atoms, whereas gamma ray emissions do not.
b.
Gamma rays and beta particles result in the formation of new atoms, but alpha particles do not.
c.
Gamma rays have mass, whereas alpha and beta particles do not.
d.
Gamma rays and alpha particles result in the formation of new atoms, but beta particles do not.
14.
What is the smallest particle of an element that maintains the properties of the element?
SC.A.2.4.2
a.
anion
b.
mixture
c.
molecule
d.
cation
15.
What properties did Rutherford use in the design of the gold foil experiment?
a.
positively charged electrons distributed in a uniform negative charge
b.
alpha particle's negative charge and random distribution of protons
c.
alpha particle's positive charge and electron's negative charge
d.
alpha particle's negative charge and gold foil's positive charge
16.
Which of the following is true for any atom?
SC.A.2.4.1
a.
mass number = number of protons = number of electrons
b.
mass number = number of protons = number of neutrons
c.
atomic number = number of protons = number of electrons
d.
atomic number = number of neutrons = number of electrons
17.
What can you conclude from the deflection of a cathode ray in a magnetic field?
SC.C.2.4.3
a.
The ray must need to travel in a vacuum.
b.
The ray must be composed of charged particles.
c.
The ray must have a positive charge.
d.
The ray must be composed of iron.
