To which period does this element belong?

To determine to which period an element belongs, you need to look at its atomic number or electronic configuration.

Definition:

• A period in the periodic table refers to a horizontal row.
• The period number indicates the number of electron shells in an atom.

How to Find the Period:

1. Using Electronic Configuration:

• Count the number of electron shells (energy levels)
• Example:
  If configuration = 2, 8, 1 → 3 shells → Period 3

1. Using Atomic Number:

• Write the electronic configuration based on the atomic number
• Then count the shells

Examples:

• Hydrogen (1) → 1 shell → Period 1
• Carbon (2,4) → 2 shells → Period 2
• Sodium (2,8,1) → 3 shells → Period 3

Conclusion:
An element belongs to a period equal to the number of its electron shells. Without specific element details, the period cannot be identified directly.