Topic 12 & 13 Particle model, forces & 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