Science - Endothermic and Exothermic Reactions

These are chemical reactions that give out heat so the temperature increases eg. coal burning to heat a room and fireworks exploding

Exothermic = energy exits

These are chemical reactions that take in heat causing a decrease in temperature eg. sherbet on your tongue and using an instant cold pack to reduce swelling

Endothermic = energy enters

These show energy transfers in chemical reactions

This happens before a chemical reaction when the particles in the reactants must collide with each other

The more collisions the faster the reaction will take place

Low concentration = few collisions

High concentration = more collisions

This is the minimum energy needed to start a reaction

This describes how quickly a chemical reaction happens

Raising the temperature increases the rate of a reaction

As heat is added to a reaction, the particles that make up the reactants gain more kinetic energy and move faster

Increasing the concentration of reactants increases the number of particles in a given volume

Low concentration results in fewer collisions

High concentration results in more collisions

Increasing the surface area increases the rate of a reaction ie. as a particle size gets smaller, the surface area increases

If you cut a potato into smaller pieces it will cook quicker than cooking a whole potato

A catalyst speeds up the rate of a chemical reaction

It lowers the amount of energy needed for a reaction to happen which makes it easier for the particles to react so there is an increase in the rate of reaction