alpha emission

beta amission

positron emisson

electron capture

The electronic configuration of Cr is [Ar] 3d⁵4s¹.(Atomic number of Cr = 24)

The magnetic quantum number may have negative value

In silver atom, 23 electrons have a spin of one type and 24 of the opposite type. (Atomic number of Ag = 47)

The oxidation state of Nitrogen in HN₃ is -3

$${}_{32}^{77}Ge$$

$${}_{33}^{77}Ge$$

$${}_{34}^{77}Ge$$

$${}_{34}^{78}Ge$$

they have isotopes

their isotopes have non-integral masses

their isotopes have different masses

the constitutents, neutrons, protons and electrons combine to give fractional masses