Naturally occurring europium (Eu) consists of two isotopes with a mass of 151 and 153. 151/63 Eu has an abundance of 48.03% and 153/63 Eu has an abundance of 51.97%. What is the atomic mass of europium?
1 Answer
Jun 23, 2014
The atomic mass of europium is 152 u.
Method 1
Assume that you have 10 000 atoms of Eu.
Then you have 4803 atoms of
Mass of
Mass of
Mass of 10 000 atoms = 1 520 394 u
Average mass =
Method 2
Total = "152.0394 u" = 152 u
Note: In both methods, the answer can have only three significant figures, because that is all you gave for masses of the two isotopes.
Hope this helps.