Question

The number of valence electrons in Chromium (atomic number 24) is:

• A. 2
• B. 3
• C. 5
• D. 6

Hint:

The valence electrons are the electrons in the outermost shell of an atom. In the case of transition metals, the \( d \)-orbitals also contribute to the valence electron count.

Answer 1

The Correct Option is C

Chromium (Cr) has an atomic number of 24, which means it has 24 electrons. The electron configuration of chromium is: \[ \text{Cr: } 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 3d^5 \, 4s^1 \] From this, we can see that the electrons in the outermost shell (the 4th shell) are \( 4s^1 \) and \( 3d^5 \). Therefore, chromium has 6 valence electrons, with one electron in the \( 4s \) orbital and five electrons in the \( 3d \) orbitals.