Question

What is the principal quantum number for the second period?

Answer 1

Principal quantum number:

• The Principal Quantum Number represents the principal energy level or shell in which an electron revolves around the nucleus.
• It is denoted by the letter n and can have any integral value except the 0 i.e. n = 1, 2, 3, 4 … ….etc.
• Principle quantum number helps to give the information of the shell to which the electron belongs.

Principal quantum number for the second period:

• The second period has the value of the principal quantum number as $2$.