Question

what is ionisation energy of atom? what is the value of it for hydrogen atom​

Answer 1

Answer:

For a hydrogen atom, composed of an orbiting electron bound to a nucleus of one proton, an ionization energy of 2.18 × 10 −18 joule (13.6 electron volts) is required to force the electron from its lowest energy level entirely out of the atom

Answer 2

The ionisation energy of an atom is defined as the energy required to knock an electron completely out of the atom.

I.E of hydrogen atom is E(infinity) - E1

= 0-(-13.6) = 13.6 eV.