Question

Which of the following compounds is metallic and ferromagnetic ?

• A. $TiO_2 $
• B. $ CrO_2$
• C. $VO_2 $
• D. $MnO_2$

Answer 1

The Correct Option is B

The question asks which of the listed compounds exhibits both metallic behavior and ferromagnetism. Let's analyze the options given:

1. $TiO_2$: Titanium dioxide is known for its applications in pigments and sunscreens but is not known to exhibit metallic or ferromagnetic properties.
2. $CrO_2$: Chromium dioxide is known to be a ferromagnetic material and is also metallic in nature. It is commonly used in magnetic tapes and exhibits a clear ferromagnetic character.
3. $VO_2$: Vanadium dioxide is interesting due to its metal-insulator transition, but it does not exhibit ferromagnetism.
4. $MnO_2$: Manganese dioxide is an antiferromagnetic material and is widely used in batteries, but it does not show metallic conductivity or ferromagnetic behavior.

Based on this analysis, we can conclude that the correct answer is $CrO_2$. It is the only compound among the options that is both metallic and ferromagnetic.

Conclusion: The compound that is metallic and ferromagnetic is $CrO_2$.