The section “chemical change or physical change” includes words and phrases such as “sometimes it is difficult” and “remember” How do these words and phrases contribute to the tone of the article?

Which statements describe polyatomic ions? check all that apply. polyatomic ions have many charges. polyatomic ions have one overall charge. polyatomic ions repel other ions to form ionic bonds. polyatomic ions attract other ions to form ionic bonds. polyatomic ions are made up of only one type of atom. polyatomic ions are made up of two or more types of atoms.

What term is missing from the central region that describes hypotheses, theories, and laws? popular predictable mathematical falsifiable

The excretory system,need answers for all: )