# How would you calculate the mass defect of Cobalt-60 given the following information?

## The isotope Cobalt-60 has a nuclear mass of 59.933820 u Mass of Proton: 1.007825 u Mass of Neutron: 1.008665 u 1 u = 931.5 MeV

Aug 16, 2017

Well, if the ""^60Co isotope has a mass of $59.933820 \cdot u$.....

#### Explanation:

We take the PARTICLE masses of $27$ $\text{protons}$, and $33$ $\text{neutrons}$. I am not going to bother with electronic mass.

And so......

$27 \times 1.007825 \cdot u + 33 \times 1.008655 \cdot u - {\underbrace{59.933820 \cdot u}}_{\text{atomic mass of isotope}}$

$= 0.56307 \cdot u$ is the mass defect.

Why did I use $\text{27 protons}$ and $\text{33 neutrons}$?