Solid's molecules have very high attraction forces, so the particles stay together and vibrate rather than any strong motion. Liquids have pretty strong attraction forces, but because they are weaker than solids, particles can move more freely, so they can slide against each other rather than vibrate. Gases have the least strong attraction forces compared to the two, so they can move everywhere, and as you know, gas is not constricted and it is everywhere, so gas is the answer.
Metal ore has other elements in it as well. Also sediment and stone might cover the ore. We don't want to have a phone with sediment on it do we? thus these few reasons are why.
This is an acid-base reaction where HF is the acid and H2O is the base (it's amphoteric and can be an acid or a base). The products would then H3O+ (the conjugate acid) and F- (the conjugate base). Now, we can simply construct a reaction using the found products and reactants. This acid-base reaction would be HF + H2O <--> H3O+ + F-.
Hope this helps!
HF the answer glad to help
