What is the mass number of an ion with 108 electrons, 158 neutrons, and a +1 charge? express your answer as an integer.

Data given

          Number of electron = 108

          Number of neutron = 158

Required

          Mass number=?

Solution  

           As we know that mass number = No of proton + No of neutron

In any neutral atom the number of proton is always equal to number of electron

So number of proton will be = 108

However the atom has +1 charge which means that one proton is less than no of electron so proton number is 107.

Put values in above formula, we will get

Mass number= 107+108

                      = 215  Mass number

the endomembrane system i think