1) students set up the apparatus you see here to separate water into its two components: hydrogen and oxygen. the illustration also shows us that hydrogen and oxygen, when uncombined, exist as diatomic molecules. based on the chemical formula of water, h2o. we would expect twice as many hydrogen bubbles to collect on the negative electrode compared to the number of oxygen bubbles collecting on the positive electrode. which chemical equation best illustrates how the total number of atoms is conserved during this chemical reaction. a) 2h2o ⇒ 2h2 + 2o b) h2o ⇒ 2h + o c) h2o ⇒ h2 + o2 d) 2h2o ⇒ 2h2 + o2 2) a synthesis reaction combines two or more elements to form a compound. in this case, hydrogen and chlorine have combined to hydrochloric acid or hydrogen chloride. which equation correctly represents this chemical reaction? a) 6h2 + 6cl2 ⇒ 12hcl b) h2 + cl2 ⇒ 2hcl c) 2h + 2cl ⇒ 2hcl d) h + cl ⇒ hcl 2nd image goes with number 2