Section 25.2
Radioactive Decay
Practice Test
1.
What happens during positron emission?
a.
A proton is converted into a neutron and an electron.
b.
An atomic explosion occurs.
c.
A neutron is converted into a proton and a positron.
d.
A proton is converted into a neutron and a positron.
Hint
2.
What conditions in the nucleus usually result in beta decay?
SC.A.2.4.3
a.
The nucleus has too many protons.
b.
The atomic mass is greater than 300 amu.
c.
The valence electrons are lost.
d.
The nucleus has too many neutrons.
Hint
3.
If a thorium-230 atom undergoes alpha decay, what are the products of the reaction?
SC.B.1.4.2
a.
actinium and a positron
b.
radium and a positron
c.
radium and an alpha particle
d.
actinium and an alpha particle
Hint
4.
A series of nuclear reactions that begins with an unstable nucleus and results in the formation of a stable nucleus is _______________.
SC.A.2.4.3
a.
the Balmer series
b.
a radioactive decay series
c.
a band of stability
d.
an isotope series
Hint
5.
The atomic number of an atom ________ when it undergoes positron emission.
SC.A.2.4.3
a.
decreases by 1
b.
increases by 1
c.
increases by 2
d.
decreases by 2
Hint
6.
What happens to the mass of an atom when it undergoes alpha decay?
SC.A.2.4.3
a.
The mass increases by 4.
b.
There is no change in mass.
c.
The mass decreases by 4.
d.
The mass decreases by 1.
Hint
7.
What ratio is used to evaluate the stability of a nucleus?
SC.A.2.4.3
a.
the atomic number to mass number ratio
b.
the electron to neutron ratio
c.
the electron to proton ratio
d.
the neutron to proton ratio
Hint
