Changes In Matter Pt1 (Physical/Chemical)- MG

Question 1

What is a physical change?

Answer 1

• It’s a transformation that doesn’t change the nature or the characteristic properties of matter. In other words, the molecules stay the same before and after the transformation.
• Physical changes don’t produce any new substances.
• Most of the time, physical changes are reversible. They can go back to the way they were before the transformation.

Question 2

What are examples of physical change?

Answer 2

Phase change, shape change, and preparing or separating a mixture.

Question 3

What’s it called when a phase change goes from solid to liquid?

Answer 3

Melting

Question 4

What’s it called when a phase change goes from liquid to gas?

Answer 4

Vaporization

Question 5

What’s it called when a phase change goes from gas to liquid?

Answer 5

Condensation

Question 6

What’s it called when a phase change goes from liquid to solid?

Answer 6

Solidification/freezing

Question 7

What’s it called when a phase change goes from solid to gas

Answer 7

Sublimation

Question 8

What’s it called when a phase change goes from gas to solid

Answer 8

Deposition

Question 9

Fill in the blank: Molecules ____ before and after a physical change.

Answer 9

Stay the same

Question 10

Fill in the blank: Physical Changes don’t produce ___.

Answer 10

New substances

Question 11

Fill in the blank: In a physical change, the characteristics of the substances involved ____.

Answer 11

Stay the same

Question 12

Fill in the blank: Physical changes are generally ____.

Answer 12

Reversible

Question 13

Match this statement with an example of a physical change: Mia makes jewelry by twisting copper wires.

Answer 13

Shape change

Question 14

Match this statement with an example of a physical change: in the 19th century, gold miners sieved sediment from the Klondike River in the hope of finding gold nuggets.

Answer 14

Separation of a mixture

Question 15

Match this statement with an example of a physical change: Jake adds food colouring to the icing for Kaylee’s bday cake

Answer 15

Preparation of a mixture

Question 16

Match this statement with an example of a physical change: Aaralyn leaves a glass of water on the counter. After a few days, the water disappears.

Answer 16

Phase change

Question 17

Does the following describe a physical change: Plants transform carbon dioxide into oxygen during photosynthesis.

Answer 17

No, this produces a new substance.

Question 18

Does the following describe a physical change: Hanna cuts the cedar planks to make a bench.

Answer 18

Yes, it’s the same but in a different form.

Question 19

What is a chemical change?

Answer 19

• A reaction that changes the nature of the substance (ex properties that are unique to the substance —> melting point, density, boiling point)
• New substance(s) are produced
• usually irreversible
• Opposite of a physical change

Question 20

What are the 5 indicators of a chemical change?

Answer 20

Formation of a gas, formation of a precipitate (solid), change in colour, change in temperature, light is given off.

Question 21

What is a “formation of a precipitate”?

Answer 21

A precipitate is formed when 2 liquids called “aqueous solutions” (water with dissolved substances inside) mix together to form a solid.

Question 22

What are the TYPES of chemical changes?

Answer 22

• Synthesis
• Decomposition
• Oxidation
• Combustion

Question 23

What is a “synthesis reaction”?

Answer 23

When 2 or more substances combine to make one new, more complex substance (ex. creation of water —> 2H+O2=H2O)

Question 24

What is a “decomposition reaction”?

Answer 24

One substance breaks down into 2 or more simpler substances.
(Ex. Salt: NaCl —> Na + Cl)

Question 25

What is an “oxidation reaction”?

Answer 25

A reaction between a substance and the oxygen in the air (usually with metals). Ex: Copper reacts with oxygen turning it green.

Question 26

Where are most of the metals found on the periodic table?

Answer 26

Left-hand side.

Question 27

What is a “combustion reaction”?

Answer 27

When a substance reacts with oxygen in the air and creates CARBON DIOXIDE AND WATER (ONLY), giving off a lot of heat, light and energy. (Only H2O and CO2 is released).

Question 28

Match this statement with an example of a chemical change (5 indicators): Coal releases lots of heat as it burns.

Answer 28

Change in temperature

Question 29

Match this statement with an example of a chemical change (5 indicators): When an antacid tablet is added to a glass of water, it frizzes.

Answer 29

Formation of a gas

Question 30

Match this statement with an example of a chemical change (5 indicators): When a potassium iodide solution (Kl) is mixed with a lead nitrate solution (Pb(NO3)2), it creates a yellow substance called lead diiodide (Pbl2).

Answer 30

Formation of a precipitate

Question 31

Match this statement with an example of a chemical change (5 indicators): Magnesium ribbon releases a bright light when heated.

Answer 31

Emission of light

Question 32

Match this statement with an example of a chemical change (5 indicators): Copper powder starts off as orange but blackens as it is heated.

Answer 32

Colour change

Question 33

What is “conservation of matter”?

Answer 33

In any physical or chemical transformation, the quantity of matter stays the same. In other words, the mass of the matter doesn’t change, because the atoms stay the same.