P6 - Molecules and Matter

Question 1

Define density?

Answer 1

Its mass per unit volume

Question 2

Which has a higher density - wood or concrete?

Answer 2

Concrete

Question 3

What is the equation for density?

Answer 3

Density = mass / volume

Question 4

What do you use to measure the mass of an object?

Answer 4

An electronic balance

Question 5

What two ways can you measure the volume of an object?

Answer 5

Measure its dimensions and do length x width x height or lower it into a measuring cylinder partly filled with water and measure the rise in water level.

Question 6

What is the density of water?

Answer 6

1000 kg/metres cubed

Question 7

True or False - objects with a density lower than water will sink?

Answer 7

FALSE - objects with a density lower than water float in water

Question 8

Which states of matter flow?

Answer 8

Liquid and Gas

Question 9

Which states of matter are fixed shape?

Answer 9

Solid, the others fit into the shape of a container

Question 10

Which states of matter have a fixed volume?

Answer 10

Solids and Liquids

Question 11

Which states of matter have a high density?

Answer 11

Solids and liquids

Question 12

How can states be changed?

Answer 12

By heating or cooling the substance

Question 13

Does the mass of a substance change when it changes state?

Answer 13

NO - when the state changes, the number of particles in the substance stays the same so the mass is the same.

Question 14

Which states have the most and least amount of energy for a fixed amount?

Answer 14

Gases have the most energy and solids have the least

Question 15

Draw the arrangement of particles of a substance in solid, liquid and gas states

Answer 15

See page 73 of text book for answer

Question 16

Describe the arrangement of particles in a solid?

Answer 16

Particles are held closely next to each other in fixed positions, they vibrate in these positions so solids keep their shape.

Question 17

Describe the arrangement of particles in a liquid?

Answer 17

They are in contact with each other, they move at random meaning a liquid doesn’t have its own shape and can flow.

Question 18

Describe the arrangement of particles in a gas?

Answer 18

They move about at random and much faster than in a liquid, they are much further apart than liquid hence their density if much less.

Question 19

True or False - temperature of a substance stays the same when undergoing a change of state?

Answer 19

True

Question 20

Define melting point?

Answer 20

The temperature at which a solid changes to a liquid

Question 21

Define boiling point?

Answer 21

The temperature at which a liquid turns into a gas

Question 22

Define freezing point?

Answer 22

The temperature at which a liquid changes to a solid

Question 23

What happens to the melting point of water when impurities such as salt are added? How can this be beneficial?

Answer 23

The melting point of water is lowered when salt is added. This means salt can be added to grit to cover roads to ensure roads don’t get icy

Question 24

What is the melting point of water?

Answer 24

0 degrees C

Question 25

What is the boiling point of water?

Answer 25

100 degrees C

Question 26

Can you understand melting and boiling points from a graph?

Answer 26

See page 75

Question 27

Define latent heat?

Answer 27

The energy transferred to a substance when it changes its state

Question 28

What does fusion mean?

Answer 28

It is used to describe melting because different solids can be joined together when melted

Question 29

True or False - evaporation occurs at the surface of the liquid when the liquid below is a boiling point?

Answer 29

T

Question 30

What temperature does evaporation occur at?

Answer 30

Any temperature