Gcc Chm152ll: Nuclear Chemistry - Radioactivity, Decay, Dating, And Other Hazards Worksheets

Name ______________________________
Section _____________
CHM152LL: Nuclear Chemistry:
Radioactivity, Decay, Dating, and Other Hazards
There is no prelab assignment this week
I. Radioactive Isotopes and Nuclear Equations
Atoms are composed of three main subatomic particles: protons, neutrons and electrons. Protons and
neutrons are found in the nucleus of an atom. The total number of protons and neutrons determines an atom’s
mass. The number of protons defines the element.
Some nuclei are unstable, so they decompose (or "decay") over time, spontaneously emitting particles and/or
energy. Such emissions are called radioactivity (or radioactive decay) and such unstable atoms are referred to
as radioactive isotopes. Different isotopes are commonly identified by their element name or chemical symbol
and their mass number. For example, uranium-235 (U-235) and uranium-238 (U-238) are two different
isotopes of the element uranium, and carbon-12 (C-12) and carbon-14 (C-14) are isotopes of the element
carbon.
Some isotopes can also be induced to decay as a result of bombardment by high-energy particles (e.g.
neutrons, electrons, and other nuclei). These kinds of nuclear changes are called nuclear transmutation.
Both radioactive decay and nuclear transmutation are examples of nuclear reactions.
Atomic Notation (or Nuclear Symbol): Shorthand for keeping track of protons and neutrons in the nucleus
mass number = A
E = Element symbol
atomic number = Z
atomic number: whole number of protons (p
+
) = whole number of electrons (e
-
) in a neutral atom.
Given the element, this can be obtained from the Periodic Table
mass number:
whole number sum of protons (p
+
) and neutrons (n) in an atom’s nucleus.
Different isotopes of an element will have different mass numbers.
Some common particles have the following atomic notation: proton =
H
neutron =
n
electron =
e
1
1
0
1 
1
0
Exercise 1: Complete the following table:
Isotope
Mass Number
# of Protons
# of Neutrons
# of Electrons
Xenon - 143
99
Mo
Thorium - 229
GCC CHM152LL: Nuclear Chemistry
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