# How to identify curium mass number?

Oct 18, 2017

Here's how you can do that.

#### Explanation:

You can identify the mass number of the most abundant isotope of curium by using the element's atomic mass.

Grab a Periodic Table and look for curium, $\text{Cm}$.

Now, in order to find the mass number of the most abundant isotope of curium, you need to take the atomic mass, which is added at the bottom of the element cell

$247.070$

and round it to the nearest whole number.

You will end up with

$247.070 \approx 247$

This means that the most abundant isotope of curium, curium-247, has a mass number equal to $247$, which means that it contains $247$ protons and neutrons inside its nucleus.

Since curium has an atomic number equal to $96$, i.e. it contains $96$ protons inside its nucleus, you can say that

$\text{96 protons " + " ? neutrons} = 247$

This tells you that curium-247 contains

$\text{no. of neutrons} = 247 - 96 = 151$

neutrons inside its nucleus.