Download Nuclear Notation Worksheet

1 Nuclear Notation Worksheet
Nuclear Notation Worksheet
CK12 Foundation Chemistry
Name ________________________________ Date ______________
Background
Each element has one or more atoms associated with it. Every atom of a particular element has
the same number of protons. A particular atom of an element does not have to have the same
number of neutrons. A group of atoms of an element must all have the same number of protons
but they may have several different numbers of neutrons. The atomic number of an atom
indicates the number of protons in its nucleus and the mass number of an atom indicates the
total number of protons and neutrons in its nucleus. Atoms with the same atomic number but a
different mass number are called isotopes.
Nuclear notation is a shorthand way of writing information about a particular atom. An example
of the accepted form of nuclear notation is shown below.
The large “X” represents the symbol for the element. The mass number is represented in the
image by the letter “A” and is positioned as a superscript preceding the X. The atomic number is
represented by the letter “Z” and is positioned as a subscript preceding the X.
Here is an example of this notation using a carbon isotope that contains six protons and six
neutrons in its nucleus.
We see a carbon atom represented with an atomic number of 6, showing this atom, like all
carbon atoms, has 6 protons in the nucleus. The mass number of 12 shows the nucleus
contains a total of 12 protons and neutrons. Since we know the carbon atom has 6 protons, a
subtraction of the atomic number from the mass number indicates the nucleus contains 6
neutrons.
Another isotope of carbon is a carbon nucleus that contains 6 protons and 8 neutrons. The
nuclear notation for this isotope of carbon appears below.
2 Nuclear Notation Worksheet
In the nuclear notation for this isotope of carbon, the mass number is 2 greater because the
nucleus contains 2 more neutrons and the same number of protons.
Exercises
1. An atom contains 3 protons, 3 neutrons, and 3 electrons. What is its atomic number?
2. An atom contains 3 protons, 3 neutrons, and 3 electrons. What is its mass number?
3. Indicate the number of protons, neutrons, and the mass number for the following nuclear
symbol.
 Number of protons = _____
 Number of neutrons = _____
 Mass number = _____
4. Indicate the number of protons, neutrons, and the mass number for the following nuclear
symbol.



Number of protons = _____
Number of neutrons = _____
Mass number = _____
3 Nuclear Notation Worksheet
5. Indicate the number of protons, neutrons, and the mass number for the following nuclear
symbol.
 Number of protons = _____
 Number of neutrons = _____
 Mass number = _____
6. Indicate the number of protons, neutrons, and the mass number for the following nuclear
symbol.
 Number of protons = _____
 Number of neutrons = _____
 Mass number = _____
7. Write the nuclear symbol for an isotope of neon whose nucleus contains 10 protons and
10 neutrons.
8. Write the nuclear symbol for an isotope of bromine whose nucleus contains 35 protons
and 45 neutrons.