Chemical Change aka Chemical Reactions
Concept of Change Change an act of altering a substance an act of altering a substance
Physical Change A change that occurs which does not change the identity of the substance
Signs of a Physical Change Melting Ice Freezing Kool-aid Tearing paper Boiling water
Chemical Changes A change that occurs causing the identity of the substance to change
New substance is formed Has different properties Mass does not change (Law of Conservation of Matter)
Indicators of a Chemical Change
Light given off
Chemical Change Presence of hot Presence of cold
Chemical Change Gas produced bubbling or fizzing bubbling or fizzing
Chemical Change Solid precipitate
Chemical Change Color change
Chemical Change Odor given off Pewwwww!
Chemical Change Smoke produced
Is it a chemical change? Decide if it is physical or chemical Then tell your reason
Smoke, color change and a temperature change A forest fire destroys acres of land. There is a lot of smoke, and the trees turn to charcoal. Chemical
Water turns brown because the cocoa is brown When making hot cocoa, clear water turns brown when you mix the cocoa in Physical
no new substance formed (melting ) Ice cream melts after it falls on the ground Physical
No new substance has formed (condensation) On a hot day water forms on the outside of a cold glass of water Physical
Color change A raw egg gets cooked Chemical
Gas formation When Alka Seltzer is dropped into water it fizzes. Chemical
the paper is changing color because the crayon is red. Red crayon changes white paper to red white paper to red Physical
The bubbles were already there, just under pressure in the bottle Soda fizzes, and bubbles as you pour it in a glass Physical
Color change and temperature change When you crack a glow stick, hydrogen peroxide mixes with other chemicals, causing it to glow and warm up. Chemical
Video time Bill Nye Bill Nye