Endothermic and Exothermic Reactions

What happens to bonds during a chemical reaction?

They broken and made

How do reactants produce products?

They molecules are rearranged

When is energy required?

To break bonds

When is energy released?

When bonds are made

What is n exothermic reaction?

When the energy out is greater than the energy in

What are examples of exothermic reactions?

* Respiration
* Combustion
* Hand warmers

What is an endothermic reaction?

When the energy in is greater than the energy in

What are examples of endothermic reactions?

* Photosynthesis
* Ice pack
* Boiling

What is bond energy?

The amount of energy needed to break or make bonds

What is enthalpy changes?

The amount of heat given out or absorbed

What does a negative enthalpy change mean?

Exothermic reaction

What does a positive enthalpy change mean?

Endothermic reaction