Question

is the particle represented by the electron configuration below paramagnetic or diamagnetic?
$1s^2 2s^2 2p^6 3s^2 3p^6 4s^1 3d^5$
paramagnetic
diamagnetic

Explanation:

Step1: Count unpaired electrons

Identify orbitals with single electrons: $4s^1$ has 1 unpaired electron; $3d^5$ has 5 unpaired electrons (Hund's rule: d-orbitals fill singly first). Total unpaired electrons = $1 + 5 = 6$.

Step2: Define paramagnetism/diamagnetism

Paramagnetic substances have unpaired electrons; diamagnetic have all paired.

Answer:

paramagnetic