Which of the following elements is not paramagnetic?

• A. Ne
• B. O
• C. Fe
• D. Cu

Answer: (A)

Verified step by step guidance

1. Recall that paramagnetism arises from the presence of unpaired electrons in an atom or ion. Elements with one or more unpaired electrons are paramagnetic, while those with all electrons paired are diamagnetic.
2. Identify the electron configurations of each element to determine the number of unpaired electrons:
3. For Neon (Ne), the electron configuration is \$1s^2 2s^2 2p^6$, which means all electrons are paired.
4. For Oxygen (O), the electron configuration is \$1s^2 2s^2 2p^4$, which has unpaired electrons in the 2p orbitals, making it paramagnetic.
5. For Iron (Fe) and Copper (Cu), both have unpaired electrons in their d orbitals, so they are paramagnetic as well.