Answer:
The new pressure of the gas comes out to be 400 KPa.
Explanation:
Initial volume of gas = V = 
Initial pressure of gas = P = 120 KPa
Final volume of gas = V' = 
Assuming temperature to be kept constant.
Assuming final pressure of the gas to be P' KPa
New pressure of gas = 400 KPa
You should read up on Proust's law, better known as the Law of Definite Proportions. This is a chemical law that defines your question more generally, on why the ratio of elements and ions are always fixed.
Basically, this compound Magnesium(II) Chloride is MgCl2 because it has the same number of protons, neutrons, and electrons all the way. This defines the properties of the compound or atom.
they move around and eventually come and join to make a solid
Answer:
A. Their numbers of atoms
Explanation:
