Why can't surflic acid and magnesium chloride make hydrofluoric acid

Nickel crystallizes in the face-centered cubic (fcc) lattice. the density of the metal is 8902 kg/m3. calculate the radius of a nickel atom.

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?

Which one of the following bonds would you expect to be the most polar? a) b–h b) n–h c) p–h d) al–h e) c–h