Changes of State

Looking at the second bullet point in more detail, the reason for this is because the number of molecules never changes. If a solid has 100 molecules and it melts it will still have 100 molecules which means it has the same mass. Let’s say if then boils and turns into a gas, how many molecules will it have?

You’re right! Still 100!! Therefore the mass is still the same.

What is a reversible change?: Your answer should include: Substance / Recover / Original / Properties
What is a chemical change?: Your answer should include: Process / Cannot / Can't / Reversed / Recover / Original / Properties
Explanation: The process cannot be reversed to recover the original properties.