A material is considered magnetic if it has which of the following properties?

• A. A large atomic radius
• B. Unpaired electrons in its atoms or ions
• C. Strong ionic bonds
• D. A high melting point

Answer: (B)

Verified step by step guidance

1. Understand that magnetism in materials primarily arises from the presence of unpaired electrons in atoms or ions. These unpaired electrons have magnetic moments that can align and produce a net magnetic effect.
2. Recall that atomic radius, ionic bond strength, and melting point are physical or chemical properties that do not directly cause magnetism, although they may influence other material characteristics.
3. Recognize that paired electrons have opposite spins that cancel each other's magnetic moments, so materials with only paired electrons are generally not magnetic.
4. Identify that the key property for magnetism is the presence of unpaired electrons, which create magnetic dipoles that can align under an external magnetic field.
5. Conclude that the correct criterion for a material to be magnetic is having unpaired electrons in its atoms or ions.