Question

The ionisation energy of a singly ionised helium ion is equivalent to:

• A. kinetic energy of first orbit
• B. energy of last orbit
• C. average energy in orbits
• D. maximum energy in orbits

Answer 1

The correct option is A kinetic energy of first orbit

The ionisation energy of a singly ionized helium ion is equivalent to the kinetic energy of the first orbit.

Singly ionized helium atom contains only 1 electron. The energy required to remove this electron completely is called ionization energy.

This electron is present in the first orbit. Hence, this energy is also equal to the kinetic energy of the first orbit.

Hence, the correct option is $A$