Question

An atom of 49K has a mass of 48.965514 amu. Calculate the binding energy in MeV per atom.

Use the masses: mass of 1H atom = 1.007825 amu

mass of a neutron = 1.008665 amu

1 amu = 931.5 MeV

Answer 1

The answer to this question is quite simple

We first have to find mass defect in amu

And this mass defect can be converted into binding energy as

1 amu = 931.5 MeV

The formula for mass defect is

Putting values in equation we get

Atomic no = 19

Number of neutron = 49-19

= 30

Mass defect = (19×1.0078) + (30×1.0087) -48.965514

= 19.1482 +30.261 - 48.965514

= 0.443686 amu

And as 1 amu = 931.5 MeV

0.443686 amu

= 0.443686 × 931.5

= 413.29 MeV

I hope this helps if you have any query or want more detailed explanation feel free to ask in the comments section below.