 Discuss with your shoulder partner  Write down your own definition and some examples in your Physical Change box on your paper

 Discuss with your shoulder partner.  When a substance changes identity to become a new substance, a chemical change has occurred!

Crash Course Video ej_SE

Physical Change  No new products or substances  The physical properties may or may not change  Often it can be reversed  A state change may occur Chemical Change  New products form  Cannot be reversed

The process in which atoms are rearranged to produce new substances. Atoms are not gained or lost, just rearranged! The substance produced has chemical properties that are different from the properties of the original substances.

 The original substances are reactants and the resulting substances are products ReactantsProduct

 Color change  Temperature change  Gas production (fizzing or bubbling)  Precipitate forms (two liquids are mixed to produce a solid)  Change in odor  Energy production (light or sound)  Cannot be reversed

A precipitate is a solid formed from a liquid solution.

Light or sound

Remember what a chemical formula is? The representation of a substance with chemical symbols and numbers. Ex. H 2 O A chemical equation is an expression used to show the relationship between the reactants and products.

 What evidence you can observe that these are chemical reactions!  RPP2ANI (Amazing Reactions) RPP2ANI  D61PdYko (Beautiful Reactions) D61PdYko

Write “Yes” or “No” on your white board.

A forest fire destroys acres of land. There is a lot of smoke, and the trees turn to charcoal. ANSWER: YES EVIDENCE: - color change, - temperature change

When making hot cocoa, clear water turns brown when you mix the cocoa in. ANSWER: No (the water is turning brown because the cocoa is brown)

An old wheelbarrow is left out in the rain and rusts. ANSWER: Yes EVIDENCE: Color change; New substance forming (rust)

On a hot day, water forms on the outside of a cold glass of water. ANSWER: No (No new substance is forming)

Ice cream melts after it falls on the ground. ANSWER: No (No new substance is forming)

A raw egg gets cooked. ANSWER: Yes EVIDENCE: Color change

When Alka Seltzer is dropped into water it fizzes. ANSWER: Yes EVIDENCE: gas formation

Crayons change white paper to red. ANSWER: No (The paper is turning red because the crayon is red.)

Soda fizzes, and bubbles rise as you pour it in a glass. ANSWER: No (The bubbles were already there, just under pressure in the bottle.)