Solids, liquids and gases

Question 1

How do you calculate density

Answer 1

Density=mass/volume

Question 2

What equation to find the pressure in a solid

Answer 2

Pressure=force/area

Question 3

What are the units for area

Answer 3

M^2

Question 4

What are the units for pressure

Answer 4

Pa for metres or N/cm^2 for centimetres

Question 5

What are the units for density

Answer 5

Kg/m^3 or Kgm^-3

Question 6

What are the units for volume

Answer 6

M^3

Question 7

What is the density of water

Answer 7

1000 kg/m^3

Question 8

How does a solid change to form a liquid

Answer 8

It melts

Question 9

How does a liquid change to form a gas

Answer 9

Boiling

Question 10

How does a gas change to form a solid

Answer 10

Deposition

Question 11

How does a solid change to form a gas

Answer 11

Sublimation

Question 12

How does a gas change to form a liquid

Answer 12

Condensation

Question 13

How does a liquid change to form a solid

Answer 13

Freezing

Question 14

What is boiling

Answer 14

-change state from liquid to gas
-happens on a hot surface in a liquid
-happens at fixed temp
-all material changes state before temp rises

Question 15

What is evaporation

Answer 15

-Changes state from liquid to gas
-takes place in environment
-can happen at any temperature even lower than boiling point

Question 16

How does evaporation happen

Answer 16

-heat energy is incident on molecules on the surface of puddle
-increases kinetic energy
-top layers of molecules gain enough KE to leave surface
-average kinetic energy of molecules decreases for the whole puddle
-decrease in temperature

Question 17

What is the structure of solid particles

Answer 17

-closely packed in a regular pattern
-high relative density
-strong forces between particles

Question 18

Describe the motion of solid particles

Answer 18

-vibrate around a fixed point
-does not expand to fill space

Question 19

Describe the structure of a liquid

Answer 19

-closely packed in a irregular pattern
-high relative density
-strong forces between particles

Question 20

Describe the motion of a liquid

Answer 20

-does not expand to fill space
-the particles slide over each other randomly

Question 21

Describe the structure of a gas

Answer 21

-very spread out
-low relative density
-weak forces between particles

Question 22

Describe the motion of a gas

Answer 22

-move with rapid motion
-expand to fill space
-move at random past each other

Question 23

What is the specific heat capacity

Answer 23

The amount of energy required to change the temperature of 1kg of a material by 1 degree Celsius

Question 24

How do you calculate the energy required using specific heat capacity

Answer 24

Energy= mass x specific heat capacity x change in temperature

Question 25

What can the specific heat capacity depend on

Answer 25

-the material -the state of material

Question 26

Do specific heat capacity questions

Answer 26

👣

Question 27

What is conduction

Answer 27

Heat transferred via vibrating o particles in solids. The particles collide and pass on energy throughout the material

Question 28

How do you reduce heat transfer by conduction

Answer 28

Use insulators such as plastic to stop the changing of temp

Question 29

What is convection

Answer 29

Occurs in fluids which is a liquid or a gas. Occurs when there is a heat source at the bottom of a fluid

Question 30

How do we reduce heat transfer by convection

Answer 30

Vacuum and heat transfer doesn’t take place. Reduce volume of fluid eg a lid on a drink

Question 31

How do you calculate the pressure in liquids

Answer 31

Pressure= density of liquid X gravitational field strength X height/depth of liquid

Question 32

What is the density of a liquid measured in

Answer 32

Kg/m^3

Question 33

How is pressure in solids different to pressure in liquids

Answer 33

-pressure from a solid acts in one direction -pressure from a liquid acts in all directions