The answer is (3) Cu2O. Copper (I) has an oxidation state of +1 (that's what the "I" indicates). You can also think of this as copper (I) having a charge of +1. Oxygen has an oxidation state of -2 (that's just a rule you have to know), and you can think of it as oxygen having a charge of -2. You need oxidation numbers in a neutral compound to add up to 0 (or charges in a neutral compond to add up to 0), so you need two Cu to balance the O, which is Cu2O.
Answer:
a
Explanation:
it is A because h20 and c02 are molecules while what make them up are atoms
43 inHg = 43 inHg*2.54cm/in = 109.22cmHg * 10 mm/cm = 1092.2 mmHg
14.7 psi = 760 mmHg
1092.2mmHg * 14.7psi / 760 mmHg = 21.13 psi
Answer: option D. 21.13 psi
All of these are compounds except oxygen because a compound is two or more different elements bonded together.