Please help with everything. Make sure to explain the mechanisms. THANKS

Which terms are used to identify pure substances

Covalent compounds: mastery test select the correct answer what is formed when atoms join together with a covalent bond? a. an ion b. a molecule c. a neutral atom d. a noble gas

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.