Question

Which orbital is the first to fill with electrons in a given principal energy level?

Answer 1

The s orbital is first to fill

Answer 2

Answer:  s orbitals

Explanation:  s orbital is the first to fill with electrons in a given principal energy level.

It has the most penetrating power out of all the 4 orbitals.

There are 4 orbitals in which the electrons are filled regularly.These are s(sharp), p(principle), d(diffused) and f(fundamental).

S orbitals are near the nucleus . The electrons are filled as per Aufbau Principle.