Genetics science biology

In which of the following belong to a category called the main group of elements? nonmetals. transition elements. halogens. alkali metals. it can be more than one answer!

List four observations that indicate that a chemical reaction may be taking place

6what is the importance of water on earth? a) it keeps the top layer of the geosphere cool b) it allows life to exist c) it provides ice at the poles d) it creates earth's blue color from space