The law of multiple proportions is..
Different compounds made of same element have different proportions by mass of those elements.
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.
Answer:
they just add heat, then it turns to water vapor
Explanation:
The first h20 is water the arrow represents adding heat, and the second h20 represent water vapor (water as a gas)
Answer: 1) only a salt and water
An acid and base reacts together to undergo neutralization to form salt and water.

where HCl is an acid and NaOH is a base to form salt (NaCl) and water
.
Answer: 2) The formula of the hydrogen ion is often written as
.
All acids dissociate in water to give
ions.
Answer: 3) Arrhenius acids are substances that ionizes to yield protons in aqueous solution.

Arrhenius bases are substance that ionizes to yield hydroxide ions in aqueous solution.

Answer: 4) A conjugate acid base pair transfers hydrogen ion.
Here
accepts a proton and thus act as a base and the corresponding
is its conjugate acid.
Answer: 5) Bronsted Lowry acid is a substance that donates protons. Bronsted Lowry base is a substance that accepts protons.
and 

is a acid which accepts proton and thus acts as base to form conjugate acid
.