Question

Quantum number n is known as the ___ and represents what about the electron in the atom?

a) Principal quantum number; the energy level of the electron.
b) Sublevel quantum number; the orbital shape.
c) Magnetic quantum number; the direction of the electron's spin.
d) Spin quantum number; the electron's speed.

Answer 1

The principal quantum number (n) is the main energy level occupied by the electron, indicating its average distance from the nucleus and its energy state.

Step-by-step explanation:

Quantum number n is known as the principal quantum number and represents the energy level of the electron within an atom. This number can be any positive integer, and it determines the main energy level occupied by the electron, with energy levels being at fixed distances from the nucleus. The higher the value of n, the greater the average distance of the electron from the nucleus, which also corresponds to the row number of the atom on the periodic table. Electrons with a higher principal quantum number are generally easier to remove from an atom, as they are less strongly attracted to the nucleus due to being farther out in space.

Bohr's model and the solutions of the Schrödinger equation both use the principal quantum number to denote the general energy states of electrons. When all wavefunctions have the same value of n, they constitute a principal shell, indicating that the electrons within have similar average distances from the nucleus.