Topic 14 & 15 Particle model, forces and matter Flashcards
1 Name the three states of matter.
solid, liquid, gas
2 Which of the three states of matter can be compressed?
gases
3 Why can gases be compressed?
particles are far apart
4 Which of the three states have a fixed volume?
solids and liquids
5 Why do substances in these states have a fixed volume?
particles are held together by bonds
6 Why do solids keep their shape?
Bonds between particles are very strong
7 Name a physical change.
any change of state named, such as melting, freezing
8 What does the density of a substance tell you?
the mass for a certain volume
9 What two quantities do you need to know to calculate density?
mass and volume
10 What are the units for these two quantities?
kg and m3; accept g and cm3
11 What are the units for density?
kg/m3 or g/cm3
12 What is the equation for calculating density?
density = mass/volume
13 What usually happens to the density of a substance when it melts?
decreases
14 Why does this happen?
particles are closer together in a solid than in a liquid
15 What happens to the mass of a substance when it melts?
stays the same
16 Is evaporating a physical or a chemical change?
physical
17 Why is evaporation a physical change?
no new substance is made
18 How is thermal energy stored in a substance?
movement of the particles
19 What does temperature tell you about the particles in a substance?
how fast they are moving/vibrating
20 What factors affect the amount of thermal energy stored in a substance?
mass, temperature, material
21 What property of a substance tells you about the movement of its particles?
temperature
22 How can you reduce the amount of thermal energy transferred between an object and its surroundings?
use insulation
23 Name two insulating materials.
wool, foam, bubble wrap, or any other sensible suggestions
24 Why does a kettle full of water store more energy than a cupful of water at the same temperature?
greater mass of water
25 Give two other quantities that affect the amount of thermal energy stored in an object.
temperature and material
26 What does specific heat capacity mean?
energy needed to raise 1kg of a substance by 1C
27 What happens to the temperature of a substance being heated when it changes state?
temperature stops rising while the change in state is happening
28 Why does this happen?
energy is being used to break bonds between particles
29 What does specific latent heat mean?
energy needed to change the state of 1kg of a substance
30 What are the units for specific latent heat?
J/kg
32 Give the three factors that affect the amount of thermal energy stored in a substance.
mass, temperature, material
33 What is the unit for specific heat capacity?
J/kg/øC
34 What symbol is used for change in thermal energy?
Q
36 What symbol is used for specific heat capacity?
c
37 What does specific latent heat meant?
energy needed to change the state of 1ÿkg of a substance
38 What are the units for specific latent heat?
J/kg
39 Describe the arrangement of particles in a gas.
far apart and moving around quickly
40 What causes gas pressure?
forces from particles hitting the walls of the container
41 How are temperature and kinetic energy related?
Temperature is a measure of the average kinetic energy of the particles.
42 What causes pressure in a gas?
forces from particles hitting the walls of the container
43 What is the unit for pressure?
pascal, or N/m2
44 Why does the pressure of a gas increase when it is heated?
particles move faster, hit the walls harder and more often
45 What name do we give the temperature at which particles would have zero energy/pressure?
absolute zero
46 What is 0K in degrees Celsius?
-273øC
47 How do we describe something that deforms but returns to its original shape when forces are removed?
elastic
48 What do we call the difference between a spring?s stretched length and its original length?
extension
49 How does the force needed to stretch a spring change as the spring gets longer?
increases
50 A graph of a relationship between two variables is a straight line through the origin. How do we describe a relationship such as this?
directly proportional
51 What word do we use to describe something that deforms but returns to its original shape when forces are removed?
elastic
52 What word do we use to describe something that deforms and does not return to its original shape when forces are removed?
inelastic
53 What does a linear relationship on a scatter graph look like?
a straight line
54 What is the difference between the graphs for a linear and a directly proportional relationship?
The graph for a directly proportional relationship passes through the origin; a graph for a linear one does not necessarily do so.
55 Describe the relationship between the force on a spring and its length, for small forces.
linear
56 Describe the relationship between the force on a spring and its extension, for small forces.
directly proportional
57 What happens to the relationship between the force on a spring and its length or extension when the forces become very large?
becomes non-linear
58 Describe the relationship between the force on a rubber band and its length.
non-linear
59 What is the spring constant of a spring?
force needed to produce a 1m extension
60 What is the equation linking the spring constant with the force and extension?
force = spring constant x extension
