C7.3 Why are there energy changes during chemical reactions?

Question 1

1. What is an exothermic reaction?

Answer 1

-energy released from breaking bonds > energy used to break them
=energy released (usually as heat)

Question 2

1. What is an endothermic reaction?

Answer 2

-energy released from breaking bonds < energy used to break them
=energy taken in (usually heat)

Question 3

1. What happens to bonds in a chemical reaction?

Answer 3

-old bonds are broken and new bonds are formed

Question 4

3. What happens when chemical bonds are broken?

Answer 4

-energy is needed (endothermic process)

Question 5

3. What happens when chemical bonds are made?

Answer 5

-energy is released (exothermic process)

Question 6

5. What does the term activation energy mean?

Answer 6

-the energy needed to break bonds to start a reaction