Essential Questions: How does evidence of chemical reactions indicate that new substances with different properties are formed? Chemical Changes Chemical Reaction •Occurs when two or more molecules interact and the molecules change into a new substance. •Bonds between atoms are broken and created to form new molecules. Physical Changes Physical Change •Changes the form or appearance of a substance. •Does not change substance into anything new. Examples •Whipping eggs •Boiling water •Dissolving sugar •Dicing vegetables Physical Changes Physical Changes •Changing the state of matter •Changing the color •Changing the temperature •Changing the shape •Changing the texture Smo oth Chemical Changes Chemical Change •When two or more substances join to form new substances with new chemical properties. Examples •Iron rusting •Gas burning •Eggs cooking •Bread rising Chemical Changes Unexpected Color Change New molecules created in a chemical reaction radiate light differently producing new colors. Examples: •Fireworks •Leaves a change color Chemical Changes Unexpected Temperature Change During chemical bonding, energy is released or absorbed making their surroundings hotter or cooler. Examples: •Adding baking soda to vinegar causes the temperature to decrease. •Body temperature increases to fight infections. Chemical Changes Combustion/Burning A chemical reaction between substances, usually including oxygen accompanied by giving off heat and or light. This is a permanent change that cannot be undone. Examples: •Wood burning •Candle •Rusting Chemical Changes Precipitates Form When a solid suddenly appears in a solution and settles to the bottom, collects on another object, or makes the solution cloudy. Examples: •Milk souring •Bath tub rings Chemical Changes Bubbles Form When gases produced in a chemical reaction are released. Examples: •Alka-Seltzer •Bubbles in sodas Check for Understanding Can you… Investigate how evidence of chemical reactions indicate that new substances with different properties are formed?

Unit 3: Chemical Changes Overview

Unit 3: Chemical Changes Overview - Page 3

Unit 3: Chemical Changes Overview - Page 4

Unit 3: Chemical Changes Overview - Page 5

Unit 3: Chemical Changes Overview - Page 6

Unit 3: Chemical Changes Overview - Page 7

Unit 3: Chemical Changes Overview - Page 8

Unit 3: Chemical Changes Overview - Page 9

Unit 3: Chemical Changes Overview - Page 10

Unit 3: Chemical Changes Overview - Page 11

of 11

Description

Free up your schedule!

Take 5 seconds to unlock