Element Abbreviation – a.k.a. Isotopic Notation
Label the Atomic Number, Symbol, and Atomic Mass on the two boxes.
16
S
Sulfur
32
16
S
32
On the left, you see an element box from the Periodic Table. On the right, there is a shorthand
notation, known as isotopic notation, which chemists use in literature. This style makes it easier
to point out isotopes (when the number of ____________ is compared to the number of
______________ in an atom). For example, chemists denote the difference between Carbon-12,
Carbon-13, and Carbon 14 in the bottom diagram. You can see that the symbol and atomic
number are the same, but the atomic mass changes depending on the number of neutrons.
To use the shorthand notation:
1. write the element symbol (X)
2. Write the Atomic Mass (A) on the side
3. Write the Atomic Number (Z) directly under the mass
4. Practice with oxygen-16 and oxygen-18.
A
Z
X
235
92
U
237
92
U
238
92
U
Which element is this? _______________________________
What is the Atomic Number? ________________
What are the Atomic Masses? _____________________________
Which one is the standard version (Look on your Periodic Table)? _________________
Which are the isotopes? ________________
35
17
Cl
37
17
Cl
38
17
Cl
Which element is this? _______________________________
What is the Atomic Number? ________________
What are the Atomic Masses? _____________________________
Which one is the standard version (Look on your Periodic Table)? _________________
Which are the isotopes? ________________
11
5
B
Which element is this? _______________________________
How many protons does this element have? ________________
How many neutrons does this element have? _______________
Is the standard version of this element (Look on your Periodic Table)? _________________