Presentation is loading. Please wait.

Presentation is loading. Please wait.

Physical and Chemical Changes

Similar presentations

Presentation on theme: "Physical and Chemical Changes"— Presentation transcript:

1 Physical and Chemical Changes

2 Physical Change A change that affects one or more physical properties of a substance Chemical identity remains unchanged Appearance, shape, or size may be altered Example: wool

3 Physical Change Change in state of matter is a physical change
Ex. Boiling, freezing, melting, subliming, deposition, condensation

4 Chemical Change A chemical change occurs when one or more substances change into entirely new substances with different properties. Example: cake

5 Chemical Change vs Properties
Burning is a change, flammability is a property Chemical properties describe which chemical changes can or cannot occur Chemical changes are the process by which substances actually change into new substances

6 Identity Change? Particles and chemical bonds get rearranged
Often times this rearrangement involves some sort of temperature change Higher temperature means higher kinetic energy This allows particles to move around faster and rearrange more easily Back to the cake example

7 How Can You Tell? Production of a gas Production of an odor
Bubbling, fizzing, foaming Production of an odor Rotting eggs, sour milk, lightning changing the smell of the air Formation of a Precipitate A precipitate is a solid formed from a reaction of 2 liquids Example: potassium iodide and lead nitrate react to form lead iodide Change in color Change in Energy Often times seen as light or felt as heat

8 Change Observation Type of Change Metal Rusting Ice Cream Melting Painting a Door Baking cookies Barbequing Chicken

9 Law of Conservation of Mass
The law of conservation of mass states that in ordinary chemical and physical changes, mass is not created or destroyed but is only transformed into other substances Discovered by Antoine Lavoiser

Download ppt "Physical and Chemical Changes"

Similar presentations

Ads by Google