The first table was arranged by atomic mass, but later mosely improved it by arranging by

The first table, created by Mendeleev, was arranged by increasing atomic mass. However, it was later changed by Mosley, who arranged it the way it is today. He organized it by atomic number.

Engineers have contribute to society in many ways like making the technology we use today or any type of power energy material

Determine the  wavelength of light emitted when an electron  in an li2+ ion  makes a transition from an orbital with n  =  6 to an orbital with n  = 5.