Answer:
a Mn atom has 5 electrons in its 3d subshell
All those 5 electrons are unpaired.
Explanation:
Step 1 : Data given
Mn = manganese
Manganese has atomic number 25
Step 2: Number of electrons
Since Manganese has atomic number 25, it means it has 25 electrons
It's complete electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵
3d⁵ = This means a Mn atom has 5 electrons in its 3d subshell.
Since there are 5 orbitals in the 3d, each electron will occupy its own orbital (this is called the Hunds rule).
Before pairing begins, the 3d orbital must be filled parallel first.
This means all those 5 electrons are unpaired.