Nuclear Chemistry Review (Solutions) – Physical Science
Name __________________________
1) What is the difference between a chemical reaction and a nuclear reaction?
a. Chemical reaction involves changes in the electrons (outside the nucleus), nuclear reactions involve
changes in the nucleus (much higher energy)
2) What are the 3 different types of particles that may be released during nuclear decay?
a. Alpha particles (He nucleus), Beta particles (electron), and Gamma Rays (high energy light)
3) What makes some isotopes ‘unstable’ that causes them to undergo nuclear decay? (consider the forces
involved)
a. When the forces inside the nucleus are no longer balanced… adding extra neutrons causes this bc it
causes the nucleus to get bigger which causes the strong nuclear force to weaken
4) What type of nuclear reactions are used in nuclear power plants?
a. Controlled fission reactions
5) What are the names of the two forces in the nucleus of an atom? Which one is attractive? Which one is
repulsive?
a. Strong nuclear force and electrical force. The strong nuclear force is attractive, the electrical force is
repulsive
6) What type of nuclear reactions are used in nuclear bombs?
a. Uncontrolled fission reactions
7) What is necessary for nuclear fusion to occur?
a. Very high temperatures
8) What type of reactions occur in the interior of a star?
a. Fusion reactions
9) How were all elements beyond Hydrogen and Helium formed?
a. During fusion inside stars
10) What is an isotope?
a. An atom of a given element that has a different number of neutrons in the nucleus, therefore a
different mass number
11) What is a half-life?
a. The amount of time a given radioisotope takes to reduce itself by half. After one half-life, half of the
radioisotope has decayed to other elements
12) What fraction of an isotope will be left after it goes through a time period of 3 half-lives
a. 1/8th
13) What is transmutation? How can it happen?
a. When an element turns into another element. Happens during nuclear decay, or can happen
artificially by bombarding the nucleus w high energy particles
14) What triggers nuclear fission?
a. High energy particles bombarding an atomic nucleus
15) What force holds together the nucleus?
a. Strong nuclear force
16) What force tries to pull a nucleus apart?
a. Electrical force (protons repelling each other)
17) What happens to the strong nuclear force as a nucleus gets larger?
a. It gets weaker very rapidly with increased distance
18) What type of nuclear radiation is the most penetrative?
a. Gamma Rays
19) What is the isotope Carbon-14 used for?
a. Dating objects with organic materials in them, fossils, cloth, etc.
20) A Geiger counter measures radioactivity, why even when we are not around radioactive materials will there
still be a reading on it?
a. Because of background radiation, many things emit low levels of radiation that are not harmful to
us… Banana’s for example.
21) What is a Transuranium element? Are they naturally occurring? Why or why not?
a. Any element with a higher atomic number than Uranium. No they are not because at that point the
nuclei are too big to be stable on there own without being artificially created. Nucleus is just too big
for the strong nuclear force to hold together the nucleus
22) In a controlled chain reaction, what ‘controls’ it? In other words how do nuclear power plants control the
chain reaction?
a. Control rods make of unfissionable material. These absorb the high energy particles that are emitted
when an atom spltis
23) Einstein’s famous equation e=mc2 says what about the energy that can be attained from even small
amounts of mass? What does ‘c’ represent in this equation?
a. An incredibly large amount of energy can be attained from even a small amount of mass. c
represents the speed of light (a very high number)
24) There are 400 grams of a certain radioisotope, if this radioisotope has a half life of 12 years, how many grams
of it will be left after 48 years?
a. 25 grams ….. cut 400 grams in half 4 times.
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