Is An Isolated Arsenic Atom In The Ground State Paramagnetic Or Diamagnetic?
The correct answer and explanation is :
An isolated arsenic (As) atom in the ground state is paramagnetic.
Explanation:
- Electronic Configuration of Arsenic:
- Arsenic (As) has an atomic number of 33.
- Its electron configuration is:
[
1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^3
] - The valence electrons are in the 4s and 4p orbitals, with the 4p subshell containing three electrons.
- Understanding Magnetism:
- An atom is paramagnetic if it has one or more unpaired electrons.
- An atom is diamagnetic if all its electrons are paired.
- Unpaired Electrons in Arsenic:
- The 4p subshell can hold a maximum of six electrons.
- In arsenic, the three electrons in the 4p orbitals follow Hund’s Rule, meaning they occupy separate orbitals with parallel spins (↑ ↑ ↑).
- This results in three unpaired electrons.
- Magnetic Behavior:
- Since arsenic has unpaired electrons, it exhibits a net magnetic moment, making it paramagnetic.
- In contrast, if all electrons were paired, the opposing spins would cancel out the magnetic moment, making the atom diamagnetic.
Conclusion:
An isolated arsenic atom in the ground state is paramagnetic due to the presence of three unpaired electrons in the 4p subshell. This allows it to be weakly attracted to an external magnetic field, confirming its paramagnetic nature.