Mass number of Ne2
An ion X2+ contains 18 electrons and 20 neutrons. Calculate the atomic number and mass no. of element X. Name the element X.
Some carbon atoms have mass number 12 and some have mass number 14. These atoms of same element of different mass numbers are called __.
If an atom A has mass number 'x' and atomic number 'y' ( yAx ) and it forms an ion by losing an electron. What can we say about the mass number of the ion?