Please help. i have 5 minutes. no links please

What does x represent in the formula for the compound xcl4?

In the 1800s, one of the statements in john dalton's atomic theory was that atoms are indivisible. later experimental evidence led to the discovery of subatomic particles such as neutrons, electrons, and protons. what happened to the indivisible atom part of dalton's atomic theory, and why?

Label a-f based on the table using c for concentrated and d for dilute