Answer:
An emerald can be described as a pure substance because it is a compound. it's a pure substance because it is an element. It's an impure substance because it is chemically combined, an impure substance because it is a mixture.
Explanation:
I think it is A as solid atoms are close and gases are far away
Hmmm hard to tell. Sorrry :(/((/(/
Please let me know when you find out, i need this question answered as well
When the reactants have higher chemical change.