Electrons in the outer shells that are not filled are called valence electrons. Valence is the number of electrons an atom must lose or gain to attain the nearest noble gas or inert gas electronic configuration. Atoms are most stable if they have a filled valence shell of electrons. Atoms transfer or share electrons in such a way that they can attain a filled shell of electrons.
Zinc is a transition earth metal with atomic number 30 and represented in the Periodic Table with the symbol ‘Zn’.
Electron configuration: [Ar] 3d104s2
Abrrivated electronic configuration: 1s22s22p63s23p64s23d10
The electrons in the outermost or highest energy level orbitals.
Hence, valence electrons in zinc are 2.