PLEASE ANSWER Scientists observe the polyatomic ion nitrate forming a compound with unknown element 'A' and predict that the chemical formula could be A2NO3. One of the scientists, Nadeen, states that this chemical formula would be impossible. Is Nadeen correct? Explain why or why not.

Which diagram represents the phase tha occurs after a solid melts?

What changes occur in the reaction indicated by the equation? check all that apply. the hydrogen nucleus loses protons. the oxygen nucleus gains protons. the bond in h2 is broken, and new bonds are formed between hydrogen and oxygen atoms. each electron associated with a hydrogen atom is shared with an oxygen atom.

Four statements about the development of the atomic model are shown below. a: electrons have wavelike properties. b: atoms have small, negatively charged particles. c. the center of an atom is a small, dense nucleus. d: atoms are hard, indivisible spheres. which order of statements represents the historical development of the atomic model? c-d-a-b c-d-b-a d— в-а — с d-b-c-a