neon-20 is a stable isotope of neon. its actual mass has been found to be 19.99244 amu.?

Question

determine the mass defect of this nuclide

Answer 1

If I understand what you need to do then you should:

1. Find the number of protons in Neon 20.
2. Find the mass of a proton.
3. Find the number of neutrons in Neon 20
4. Find the mass of a neutron.
5. Multiply (1) x (2) and (3) x (4) and sum the two values.
6. Do 19.99244 - (5) and get the defect.

Answer 2

That is fairly straightforward. Just take the mass of a Hydrogen-1 atom and multiply by 20 and then subtract your Neon mass.