Seven
Elements do not contain more than 7 electron shells.
Quick answer: Exothermic reactions mean that heat has escaped the system. The answer is A. Heat is released.
Answer:
2Cu + S ~~~> Cu2S Copper (C) reacts with sulfur (S) to form copper sulfide as shown in the equation. A scientist adds 12.7 grams of Cu to 3.2 grams of S to start the reaction.
Explanation:
6g of hydrogen gas is my answer. I'm sorry if I'm wrong.