Valence Electrons in Thorium (Th)

Valence Electrons in Thorium

Determine the number of valence electrons in Thorium (Th, Element 90)

Step 1: Look up the electronic configuration for Thorium

The abbreviated (condensed) ground electronic configuration for Thorium is:

[Rn] 6d² 7s²

Calculate Electronic Configuration for Thorium

Step 2: Identify the outermost electrons using the electronic configuration

Electrons in atomic orbitals outside the [Rn] core are the outermost electrons:

6d² 7s²

Step 3: Use the principle quantum number to identify the valence electrons

Extract the principle quantum number, n, and number of electrons from the electron configuration:

The outermost electrons with the largest principal quantum number (in this case, n = 7) are valence electrons.

Answer

Thorium (Th) has 2 valence electron(s).