Chemistry Unit Test

Question 1

What happens to water particles when they’re frozen?

Answer 1

they expand

Question 2

why do ice cubes float?

Answer 2

because frozen water is less dense than liquid water since it expands

Question 3

Positively charged particles are called

Answer 3

protons

Question 4

the nucleus of an atom contains…

Answer 4

protons and neutrons

Question 5

The smallest particles of an atom are

Answer 5

electrons

Question 6

Molecules are smaller than atoms: True of False?

Answer 6

False

Question 7

Is water a compound? Explain

Answer 7

Yes because it is made up of hydrogen and oxygen

Question 8

Dirt is a pure substance. True of False?

Answer 8

False, it is a mixture

Question 9

The three states of matter are

Answer 9

solid, liquid and gas

Question 10

The two states of matter that have no defined shape are

Answer 10

liquid and gas

Question 11

The state of matter that has molecules farthest apart is…

Answer 11

gas

Question 12

When you cool a gas it becomes a…

Answer 12

liquid

Question 13

when you heat a liquid it becomes a…

Answer 13

gas

Question 14

when you cool a liquid it becomes a

Answer 14

solid

Question 15

when you heat a solid it becomes a

Answer 15

liquid

Question 16

What do chemists do?

Answer 16

study the properties of matter

Question 17

When something dissolves in a liquid it…

Answer 17

disappears into the liquid

Question 18

The iodine test checks for…

Answer 18

starch

Question 19

If there is starch in a substance, what colour will the iodine test show?

Answer 19

purple

Question 20

the scale of ph is from

Answer 20

0-14

Question 21

0-6 on the ph scale is considered…

Answer 21

acid

Question 22

7-14 on the ph scale is considered…

Answer 22

base

Question 23

Human blood’s ph is…

Answer 23

7.4

Question 24

is stomach juice an acid or a base?

Answer 24

acid

Question 25

Food colouring diffuses quicker in hot or cold water?

Answer 25

hot

Question 26

Decantation

Answer 26

a method to separate the mixtures of solids and liquids

Question 27

Breaking a branch off a tree is an example of what kind of change?

Answer 27

physical change

Question 28

The order of steps taken in a science lab is (6)

Answer 28

Question, hypothesis, materials, procedure, observations, and conclusions

Question 29

An observation is

Answer 29

what you actually see, hear, smell, taste or feel

Question 30

An inference is

Answer 30

a guess based on what you observe

Question 31

How do you remove salt from soil?

Answer 31

Pour water through the soil because the salt will dissolve and will go through the soil in the water

Question 32

If you are making a water filtration system in a funnel, how should you put the layers? Draw a filter and show the layers from the bottom too top using sand, gravel and pebbles

Answer 32

From largest to smallest: Pebbles, then gravel, then sand