Exothermic and endothermic reactions

Endothermic reaction

A reaction in which energy is ABSORBED by matter. Energy flows into the system from the surroundings generally in the form of heat (heat is not being released, it's being absorbed) (getting colder)

Exothermic reaction

A reaction where energy is RELEASED by matter. Energy flows from the system to the surroundings generally in the form of heat. (Heat is being released) (getting hotter)

Products

In an endothermic reaction do the products or reactants have more energy

Reactants

In an exothermic reaction do the products or the reactants have more energy

Bond energy

The amount of energy needed to break a molecule into its components atoms

True or false Answer: true

True or false? All atoms of molecules are held by chemical bonds.

True or false Answer: false

True or false? Energy is not released as bonds are formed.

True or false Answer: false

True or false? Every chemical bond has the same bond energy

Examples of exothermic reactions

•Glow sticks release energy as light • exothermic reactions are used as a heat source for example the flameless Ration heater that people in the military use to heat up food.

Examples of endothermic reactions

•photosynthesis, heat is absorbed by plants to make their own food •cold pack