A type of matter made up of a combination of elements is called a compound. for example table salt, is made up of two elements that by themselves are lethal but chemically combined cancel each other out there for becoming edible.
Answer: Next time you create a question, add an image or PDF. Because I do not know the question. So, may you please create a new question?
<span>As the gases go higher in the atmosphere they start to compose or join together</span>
The answer to number 1 is D and the answer for the second one is 2
^-^
