Chemical Reactions

Isabella Droz

Physical Changes

Physical Changes are when objects or substances undergo a change that does not change their chemical composition. You'll know when an object has been changed physical when the composition of a substance changes or one or more substances combine or break up to form new substances.

For example: Chopping wood into pieces would be a physical change

Chemical Changes

Chemical reaction occurs due to the collision between the molecules of reactants which are in rapid motion in a chemical reaction. You'll know when an object has undergone a chemical change when the solution changes color, when a solid precipitates (a precipitation reaction), when the solution begins to bubble (which means that a gas is the product of the reaction), when the solution gives off heat (exothermic reaction),etc.

For example: Firework explosions

Precipitate, Exothermic and Endothermic

A precipitate process is basically double displacement reactions which involve the formation of solid residue that is called as a precipitate.

A precipitate process example would be Rain, snow, sleet, hail, fog, and other forms of water that comes from the sky.

An exothermic process releases heat, and causes the temperature of the immediate surroundings to rise.

An endothermic process absorbs heat and cools the surroundings. An example of an exothermic process is making ice cubes. An example of an endothermic process would be melting ice cubes.