Unit 7 Lesson 1

Question 1

What was the purpose of the Physical and Chemical Changes Lab?

Answer 1

1. To know the difference between a physical and chemical change through experimenting.
2. To identify a chemical change and physical change by looking for signs of both.

Question 2

Identify the physical changes of matter and provide examples.

Answer 2

Physical change: a change that affects one of more physical properties of a substance. They occur when a substance changes from one form to another.
Examples:
-Turning sheep wool into a sweater.
-Filling an ice cube tray with water, and putting it into the freezer.
-Mixing green and red marbles.
-Boiling water
-Breaking glass
-Dissolving sugar in water

Question 3

Describe how temperature influences chemical change.

Answer 3

At higher temperatures, the particles in a substance have more average kinetic energy. They move around more freely, and rearrange more easily.
Ex.
-Burning
-Cooking

Question 4

Differentiate between physical and chemical changes.

Answer 4

Physical- Does not change the chemical identity of a substance, only its appearance.
Chemical- A substance’s identity changes because its chemical makeup changes.

Question 5

Identify signs of chemical changes in matter.

Other fat, fricken, snakes literally bully people everyday, even Evan!

Answer 5

-A physical change usually accompanies a chemical change.
1. Odor
2. Fizzing
3. Foaming
4. Sound
5. Light
6. Boiling –> boiling water is physical, boiling something and water is chemical
7. Precipitate forms
8. Energy (heat)
9. Endothermic - cooling
10. Exothermic - warming

Question 6

Describe the Law of Conservation of Mass and provide examples.

Answer 6

The LCM states that in ordinary chemical changes, Mass is not created or destroyed but is only transformed into different substances.
Examples:
-Different appearance, same parts (robots).
-Vinegar and baking soda –> make dioxide gas.
-Burning wood
-Melting ice in a container

Question 7

Define physical change.

Answer 7

Does not change the chemical identity of a substance, only its appearance.

Question 8

Define chemical change.

Answer 8

A substance’s identity changes because its chemical makeup changes.

Question 9

Define Law of Conservation of Mass.

Answer 9

The Law of Conservation of Mass states that in ordinary chemical changes, Mass is not created or destroyed but is only transformed into different substances.

Question 10

What is an element?

Answer 10

A substance that cannot be chemically broken down into a simpler substance without losing its properties.