Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components. A chemical substance is composed of one type of atom or molecule
Protons and neutrons.
Note: They probably are ABOUT the same mass. Don't think they are exactly the same.
Hope this helps!
Well people say the world's going to end soon so people need to find another planet to live on they're thinking about Mars at the moment
Answer:
can you send me a picture of what layer a and look b look like and then I will be able to evaluate
