physics 6

Question 1

Which two quantities do you need to measure to find the density of a solid or liquid?

Answer 1

mass and volume

Question 2

What happens to the particles in a substance if its temperature is increased?

Answer 2

they move faster and the energy in their kinetic energy store increases

Question 3

Why are changes of state physical changes?

Answer 3

no new substances are produced and the substance will have the same properties as before if the change is reversed

Question 4

Why is the mass of a substance conserved when it changes state?

Answer 4

the number of particles does not change

Question 5

What is the internal energy of a substance?

Answer 5

the total kinetic energy and potential energy of all the particles in the substance

Question 6

Why does a graph showing the change in temperature as a substance cools have a flat section when the substance is changing state?

Answer 6

the energy transferred during a change in state causes a change in the internal energy of the substance

Question 7

What is the name given to the energy transferred when
a substance changes state?

Answer 7

latent heat

Question 8

What is the specific latent heat of a substance?

Answer 8

the energy required to change the state of one kilogram of that substance with no change in temperature

Question 9

What is the specific latent heat of fusion as a substance?

Answer 9

the energy required to change one kilogram of the substance from solid to liquid at its melting point,
without changing its temperature

Question 10

What is the specific latent heat of vaporisation of a substance?

Answer 10

the energy required to change one kilogram of the substance from liquid to vapour at its boiling point,
without changing its temperature

Question 11

On a graph of temperature against time for a substance being heated up or cooled down, what do
the flat (horizontal) sections show?

Answer 11

the time when the substance is changing state and the temperature is not changing

Question 12

What property of a gas is related to the average kinetic energy of its particles?

Answer 12

temperature

Question 13

!!!!

what are the arrangements of solids

Answer 13

• particles very close together
• aranged in regular pattern
• vibrate but do not move from place to place

Question 14

what are the arrangements of liquids

Answer 14

• particles close rogether
• not aranged in regular pattern
• can move around eachother

Question 15

what are the arrangements of gases

Answer 15

• particles are very far apart
• not aranged in any pattern
• moving very rapidly

Question 16

what is density

Answer 16

the density of a material tells us the mass for a given volume

Question 17

1. what does high density mean
2. what does low density mean

Answer 17

1. high density -> it has lots of mass packed into its volume so the particles are tightly packed together with very little space between them, and wont be able to float
2. low density -> it has a lower mass packed into its volume so the particles are loosely packed together with plenty of space between them, and will be able to float

Question 18

what is the equation for density

Answer 18

p = m/v

Question 19

what is the unit for density

Answer 19

kg/m^3

Question 20

what is the unit for volume

Answer 20

m^3

Question 21

what is the unit for mass

Answer 21

kg

Question 22

1. what density do solids have?
2. why?

Answer 22

1. solid usually have a high dentity
2. because the particles are packed closely together, so the solids have a lot of mass for their volume

Question 23

1. what density do liquids have?
2. why?

Answer 23

1. liquids usually have a high density
2. because the particles are close together, so liquids have a lot of m ass for their volume

Question 24

1. what density do gases have?
2. why?

Answer 24

1. gases usually have a low density
2. because the particles are very far apart, so gases have small mass for their volume

Question 25

what may be an exception for a solid to have a low density?
example –> polystrene

Answer 25

(polystrene) has a very open structure an is full of air spaces, so it has a small mass for its volume

Question 26

what types of energy do particles have ?
(2)

Answer 26

• kinetic energy
• potential energy(intermolecular and chemical bonds)

Question 27

what is internal energy

Answer 27

• energy stored in a system by the particles

Question 28

what is internal energy the total of

Answer 28

• internal is the total energy and potential energy of all particles(atoms and molecules) that make up a system

Question 29

what happens as we heat a solid

Answer 29

• if we heat a solid, we increase the internal energy. At some point, the solid can turn into a liquid(melting)