Question

In the modern periodic table, the period indicates the value of

• A. Atomic number
• B. Atomic mass
• C. Principal quantum number
• D. Azimuthal quantum number

Answer 1

The correct option is C

Principal quantum number

Just take a look at the periodic table, you will understand it.

If we write the electronic configurations of elements from different periods, they always start with the next number, indicating the increase in principal quantum number.

We can observe that the period number indicates the average energy level of orbitals or number of shells present in the atom and we know that principal quantum number (n) represent the shells in an atom. Hence period in the periodic table indicates the Principal quantum number (n) i.e. number of shells.