Science Yr 9 module 2

Question 1

Who is Robert Brown and what is his significance in the discovery of particle/molecule movement?

Answer 1

Robert brown is a botanist who in 1827 discovered that pollen particles made a jiggling movement in water, later on naming his observation the ‘Brownian Motion’.

Question 2

Do solid particles move around or vibrate on the spot?

Answer 2

Vibrate on the spot

Question 3

Can liquid particles move around?

Answer 3

By sliding over each other

Question 4

Can liquid particles be compressed?

Answer 4

No, because the particles are touching the neighbouring particles

Question 5

Can liquid particles flow?

Answer 5

Yes, by sliding over each other

Question 6

How many types of material does a substance have?

Answer 6

Only one

Question 7

What is a molecule?

Answer 7

More than one atom chemically joined/bonded together

Question 8

What is the name of when several of the same type of atom are joined together?

Answer 8

An element

Question 9

What is the name of several different types of atoms are joined together?

Answer 9

A compound

Question 10

What is sublimation?

Answer 10

When a substance (iodine + carbon dioxide for example) change directly from a solid state to a gas state

Question 11

What are the 4 main properties that a type of substance depends on?

Answer 11

1. Arrangement of particles
2. Size and shape
3. How strong the forces between the particles are
4. How they move

Question 12

What are the names of change of state?

Answer 12

Melting (solid - liquid)
Freezing (liquid - solid)
Boiling/Evaporation (liquid - gas)
Condensation (gas - liquid)
Sublimation (Gas to solid or solid to gas)

Question 13

Can gas be compressed?

Answer 13

Yes, because it has lots of room the compress

Question 14

Can gas flow?

Answer 14

Yes, because the particles can move around

Question 15

What is diffusion?

Answer 15

The spreading of particles in a certain area from high concentration to low concentration

Question 16

What are the three variables of diffusion?

Answer 16

Temperature, size and gradient

Question 17

Aerosol

Answer 17

Small peices of solid or droplets of liquid suspended in gas

Question 18

Brownian motion

Answer 18

A random jiggling movement of suspended particles in a liquid, making small collisions

Question 19

Deposition

Answer 19

gas to solid

Question 20

Endothermic

Answer 20

Transfer of energy from surroundings

Question 21

Exothermic

Answer 21

The transfer of energy to surroundings

Question 22

Subliming

Answer 22

solid to gas

Question 23

Vapour

Answer 23

A gas phase of solid or liquid

Question 24

What are atoms?

Answer 24

They make up everything, they are extremely small particles which are the building blocks of life

Question 25

What are elements?

Answer 25

Made up of only one type of atom

Question 26

What are compounds?

Answer 26

Two or more elements chemically bonded together

Question 27

What are mixtures? and an example?

Answer 27

Two or more elements or compounds that are not chemically bonded together, (e.g air)

Question 28

What are molecules?

Answer 28

Two or more atoms bonded together

Question 29

Who dicsovered that the Brownian motion and what was the mystery behind the random movements?

Answer 29

Albert Einstein later on named this the Brownian motion, this was because of invisible water particles in the liquid moving the solid particles in different and random directions

Question 30

What are the three states of matter?

Answer 30

Solid, liquid and gas

Question 31

What type of gas is found in whipping cream?

Answer 31

Nitrous oxide (N2O)

Question 32

What matter is always present in foam?

Answer 32

Gas

Question 33

What is it called when you burn diesel and pieces of solid appear?

Answer 33

Particulates

Question 34

What is deposition?

Answer 34

Gas to solid

Question 35

What do melting points rely on?

Answer 35

How strong the forces are between the particles

Question 36

What is the melting point of aluminium?

Answer 36

1538 degrees

Question 37

What is the melting point of iron?

Answer 37

660 degrees

Question 38

What is the melting point of zinc?

Answer 38

420 degrees

Question 39

In an endothermic change does energy transfer from/to the surrounding?

Answer 39

from

Question 40

In an exothermic change does energy transfer from/to the surroundings?

Answer 40

to

Question 41

What does endothermic change include?

Answer 41

Melting and evaporating

Question 42

What does exothermic change include?

Answer 42

Freezing and condensing

Question 43

What year was it when scientists had discovered 60 elements in total?

Answer 43

1860

Question 44

What is table salt?

Answer 44

Sodium chloride