Can someone please help me on these

What happened to the amount of carbon dioxide in the atmosphere from 2010–2017?

What is a main difference between a mixture and a pure substance? a mixture is only a liquid, but a pure substance can be in any state.a mixture looks the same throughout, but a pure substance does not.1 a mixture can vary in composition, but a pure substance has a set composlo a mixture can be made up of a single compound, but a pure substance car

Can someone me out on this question for my national 5 chemistry homework