reading this section you will be able to do the following:
an atom using its chemical notation.
to understand nuclear reaction equations.
What is the difference
between chemical reactions and nuclear reactions?
Nuclear reactions can be described
mathematically in much the same way as chemical reactions. We
commonly express these reactions by equations, although there
is a unique difference in the nature of the reactions. The principle
difference between them lies in how the reaction occurs, specifically
how the atom is affected. Chemical reactions involve an atoms
electrons while nuclear reactions involve the atoms nucleus.
a nuclear reaction equation
In order to write an
equation for a nuclear reaction, we must first establish some
basic rules. Each of the elements involved in the reaction is
identified by the chemical symbol. Two numbers are attached to
the symbol. The number at the upper right is the mass number,
also known as the A number. The 'A' number describes
the atomic weight of the atom and identifies the number of protons
and neutrons in the nucleus. The number at the lower left
is the atomic number, or Z number. The 'Z'
number describes the number of protons in the nucleus and
determines the type of atom.
symbol for Uranium-238 =
This shows you
that Uranium has a mass number of 238 and an atomic number of
Symbols are also
utilized to represent alpha and beta particles.
symbol for an alpha particle =
The symbol for a beta particle is
chemical symbol for a neutron =
Can you determine
the mass number and atomic number of the neutron?
Now that we know what these symbols
represent, let's see how they can be applied to a nuclear equation.
Uranium-238 is an isotope, which undergoes alpha decay to produce
Thorium and gamma rays. This is expressed mathematically by the
Note that when the mass numbers on
each side of the equation are added together that they are equal.
The same principle is true for the atomic numbers, and it shows
that none of the atomic particles have been lost. One way to check
to see if you have written the proper nuclear equation is to make
sure both sides of the equation have the same number or atomic
A nuclear reaction can be described by an equation, which must be balanced.
The symbol for an atom or atomic particle includes the symbol of the element, the mass number, and the atomic number.
The mass number, which describes the number of protons and neutrons, is attached at the upper left of the symbol.
The atomic number, which describes the number of protons in the nucleus, is attached at the lower left of the symbol.