How many valence electrons does mercury have?

Step 1: Define the Problem

Identify the number of valence electrons in a mercury atom.

Step 2: Break Down the Problem

1. Determine the electron configuration of mercury.
2. Identify the valence shell and count the electrons in it.

Step 3: Apply Relevant Concepts

• Mercury (Hg) has an atomic number of 80.
• The electron configuration of mercury is: $[Xe] 4f^{14} 5d^{10} 6s^2$.

Step 4: Analysis, Verify and Summarize

• The valence electrons are those in the outermost shell.
• For mercury, the outermost shell is the 6th shell, containing the $6s^2$ electrons.

Final Answer

Mercury has 2 valence electrons.