Which from following metal nanoparticle is used for coating the filter material that acts as effective bacterial disinfectant?

Which from following metal nanoparticle is used for coating the filter material that acts as effective bacterial disinfectant?

A container contains equal masses of $\mathrm{H}_2, \mathrm{He}$, $\mathrm{CO}_2$ and Ne at a certain temperature. Which of the following gases exerts minimum partial pressure?

What type of overlap is involved in the formation of $\mathrm{C}-\mathrm{H}$ bonds in acetylene molecules?