P6 - Molecules And Matter (PAPER 1)

Question 1

What is the formula for density

Answer 1

Density (kg/m^2) = mass (kg) / volume (m^2)

Question 2

How can you tell if an object floats in water by its density

Answer 2

Objects with a lower density than water (<1000kg/m^2) float in water

Question 3

Are particles in different states of matter able to flow

Answer 3

Solid - no
Liquid - yes
Gas - yes

Question 4

Can the volume of different states of matter be changed

Answer 4

Solid - fixed
Liquid - fixed
Gas - can be changed

Question 5

Can the shape of different states of matter be changed

Answer 5

Solid - fixed
Liquid - Fits the shape of container
Gas - Fills container

Question 6

What are the density of different tastes of matter

Answer 6

Solid - high
Liquid - Medium
Gas - Low

Question 7

Why does the mass of a substance stay the same when it changes state

Answer 7

Because the number of particles stay the same

Question 8

What are the melting and boiling points of substance and what are they for water

Answer 8

The temperature where the substance melts and boils at

Water melts at 0C, Water boils at 100C

Question 9

What is the diffference between boiling and evaporating

Answer 9

Boiling happens at the boiling point

Evaporating happens below the boiling point

Question 10

What is needed to melt a solid or boil a liquid

Answer 10

Energy

Question 11

How does increasing the temperature of a substance affect its internal energy

Answer 11

It’s internal energy increases

Question 12

What happens to the particles when a substance is heated

Answer 12

They gain more energy and start to vibrate faster, until they vibrate fast enough to break apart the bonds holding them in place

Question 13

What is latent heat

Answer 13

The energy needed for a substance to change its state without changing its temperature

Question 14

What is the latent heat of fusion

Answer 14

The amount of energy needed to change the state of 1kg of a substance without changing its temperature

Question 15

What is the formula for the specific latent heat of fusion

Answer 15

Specific latent heat of fusion (J/kg) = energy (J) / mass (kg)

Question 16

Why do gases exert pressure

Answer 16

Because of the random impacts of gas molecules on surfaces that are in contact with the gas

Question 17

How is the pressure of a gas in a sealed chamber affected by changing the temperature of the gas

Answer 17

• the molecules move faster so they hit the surfaces more
• this means that the number of impacts per second is higher
• this means that the total force of the impacts increase