Density and particle model

Question 1

What is the definition of density?

Answer 1

Density is the amount of mass per unit volume.

Question 2

What is the word equation for density?

Answer 2

density = mass/volume

Question 3

What is the symbol equation for density?

Answer 3

ρ = m/V

Question 4

What are some common units of density?

Answer 4

kg/m^3

Question 5

Describe how to find the volume of a regular solid?

Answer 5

Use a ruler to measure the proportions and use the a formula to calculate the volume.

Question 6

Describe how to find the volume of an irregular solid?

Answer 6

You grab an eureka can, use a measuring cylinder to see the volume of the displaced water. The volume of the displaced water is equivalent of the volume of the object.

Question 7

How would you describe particles of solid objects in the atomic model?

Answer 7

Regular patterns, packed together.

Question 8

Do solids have an fixed volume?

Answer 8

Yes

Question 9

How do particles in a solid move?

Answer 9

They cant flow so the particles vibrate.

Question 10

Can you easily compress solids or liquids?

Answer 10

No

Question 11

Can you easily compress gas?

Answer 11

Yes

Question 12

What type of shape do liquids have?

Answer 12

Unfixed shape

Question 13

Do liquids have a fixed volume?

Answer 13

Yes

Question 14

Do the particles of a liquid flow?

Answer 14

Yes

Question 15

How do gas particles move?

Answer 15

Quickly and randomly.

Question 16

How can you change the state of a substance?

Answer 16

Adding or taking away energy.

Question 17

What is the particle model useful for?

Answer 17

The idea that solids, liquids and gases are all made up of particles in different arrangements is useful to explain the states of matter and the differences in their density: solids are more dense than gases as there are more particles in a given volume than gases have.

Question 18

Describe how to find the volume of a regular solid.

Answer 18

Use a ruler to measure the length, width and height of the object and use them to find the volume. Place the object on a balance to find the mass. Find the density by dividing the mass by the volume.

Question 19

Describe how to find the volume of an irregular solid

Answer 19

Place the object on a balance to find its mass. Fill a displacement can with water and let it drip until it no longer drips. Place the irregular object into the displacement can with a measuring cylinder under the spout. The volume of water that is displaced out of the can by the object is the same as the volume of the object. find the density by dividing the mass by the volume.

Question 20

What other equipment could be used to measure length, if required to a more precise value?

Answer 20

A micrometer or a set of Vernier callipers.

Question 21

When is mass conserved?

Answer 21

Always during changes of state; melting, freezing, boiling, evaporating, condensing and subliming.

Question 22

What makes a change of state different to a chemical change?

Answer 22

They are physical changes, so the material will recover its original properties if the change is reversed.

Question 23

What is internal energy?

Answer 23

The total kinetic energy and potential energy stored inside a system by the particles (atoms and molecules) that make up the system.

Question 24

How does heating an object change the internal energy?

Answer 24

It increases the energy of the particles that make up the system to either increase the temperature or cause a change of state.

Question 25

What does the increase in temperature of a system depend on?

Answer 25

The mass of the substance, the type of material and the energy input.

Question 26

What is the word equation that relates the change in thermal energy of a system to the factors that it depends upon?

Answer 26

change in thermal energy = mass x specific heat capacity x temperature change

Question 27

What is the symbol equation that relates the change in thermal energy of a system to the factors that it depends upon?

Answer 27

∆E = m c ∆θ

Question 28

What are the units of specific heat capacity?

Answer 28

J/kg °C

Question 29

What is the specific heat capacity of a substance?

Answer 29

The specific heat capacity of a substance is the amount of energy required to raise the temperature of 1 kg of the substance by 1 °C.

Question 30

What is latent heat?

Answer 30

The energy needed for a substance to change state is called latent heat. When a change of state occurs, the energy supplied changes the energy stored (internal energy) but not the temperature.

Question 31

What is the specific latent heat of a substance?

Answer 31

The specific latent heat of a substance is the amount of energy required to change the state of 1 kg of the substance with no change in temperature.

Question 32

What is the word equation for the energy for a change of state?

Answer 32

energy for a change of state = mass × specific latent heat

Question 33

What is the symbol equation for the energy for a change of state?

Answer 33

E = m L

Question 34

What are the units of specific latent heat?

Answer 34

J/kg

Question 35

What is the specific latent heat of fusion?

Answer 35

It relates to the change of state from solid to liquid

Question 36

What is the specific latent heat of vaporisation?

Answer 36

It relates to the change of state from liquid to vapour

Question 37

It relates to the change of state from liquid to vapour

Answer 37

The pressure produces a net force at right angles to the wall of the gas container (or any surface).

Question 38

What are the units of pressure?

Answer 38

Pascals, Pa

Question 39

What is work?

Answer 39

The transfer of energy by a force.

Question 40

When work is done on a gas, what happens to the gas?

Answer 40

The internal energy increases and it can also cause an increase in temperature.