Fermium is element number 100, with the symbol Fm. Its name comes from Fermi, called “the father of nuclear power.”
Atomic number 100(257)
FmFermiumフェルミウム (ferumiumu)
Symbol
Fm
Atomic weight
(257)
Place in the table
Period 7 · Actinoids
The number in parentheses is not an atomic weight. It is the mass number of one radioactive isotope of the element.
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
A physicist’s name
Fermium was discovered in 1953, the same year as einsteinium. With atomic number 100, it is the hundredth element.
Where it sits on the table
The fifteen elements from actinium to lawrencium are called the actinoids. On the Room of the Elements table they are in the lower of the two rows set apart at the bottom.
Think about it
Q1Whose name would you give to element number 100?
Q2Do you know anyone else called “the father of” something?
Q3Can you name the two elements found in 1953?
There is no single right answer. Talking it over with someone at home is a good way to learn.
Did you know? — Udagawa Yōan, who coined the Japanese words for hydrogen and oxygen, is called “the father of Japanese chemistry” in a research paper.