What is mass number?

What is the mass number for B?

What is meant by mass number?

What is the meant by mass number ?

There are 14 protons and 13 neutrons in the nucleus of an atom. What is its mass number ?

._(4)Be^(7) captures a K electron into its nucleus .What is the mass number and atomic number of the nuclide formed ?

._(4)Be^(7) capaires a K electron into its nucless .What is the mass number and atomic number of the nuclide formed ?