Question

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

Answer 1

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

Answer 2

Answer:

267.

Explanation:

Mass number may be defined as the sum of the number of  neutrons and number of  protons.

Mass number = No. of protons + No. of neutrons.

The atoms contains equal number of protons and equal number of electrons in a neutral atom. The ions has +1 charge and contains 108 electrons, it means the ion has losses one electron, the number of proton must be 109.

Mass number = 109 + 158.

Mass number = 267.

Thus, the answer is 267.