C1: Particles and Changing State Flashcards
Can you compress a solid?
No
Does a solid have a ‘fixed shape’?
YES
Can you see the particles that make up materials?
No - they are too small to see.
Can you compress a gas?
Yes - because its particles are far apart
What is meant by the properties of a material?
The features of the material e.g. is it strong
Identify the 3 states of matter.
Solid
Liquid
Gas
Does a liquid have a fixed shape?
No - liquids can take the shape of the container that they are poured into.
Does a liquid flow? (can it be poured?)
Yes- because its particles can roll around each other.
Describe the particles in a solid.
Neatly arranged
Vibrating
All touching
What is a mixture?
A mixture is something that is made from lots of different types of particles e.g. air is a mixture of different particles.
Which state is shown below?
Liquid
Which state is shown below?
Gas
Does a gas have a fixed shape?
No - they can take the shape of the container that they are in e.g. a balloon
What is matter?
The ‘stuff’ that everything is made from.
We say that all materials are made from tiny pieces called…
……particles
Describe the particles in a liquid.
Not an orderly arrangement
Moving around one another
Mostly touching
Which state is shown below?
Solid
Describe the particles in a gas.
Randomly arranged
Moving around
Not touching
Can you compress a liquid?
No - its particles are too close together.
What is meant by a state?
Whether something is a solid, liquid or gas.
Melting and freezing are both examples of…
changes of state
You are given 3 unknown solids.
Describe how you could identify the substances by using their melting points.
Heat each substance until they melt and record their melting points.
Look up the melting points of different solids on the internet.
Compare your melting point to the ones from the internet to identify the substance.
When a substance changes from a liquid to a solid we call it…
……freezing
When a substance changes from a solid to a liquid we call it…
……melting
What is meant by the melting point of a substance?
The temperature that a substance begins to melt at.
What temperature does ice begin to melt at?
0 °C
Describe what happens to water paricles when an ice cube melts.
- Water particles in ice are close and neatly arranged.
- The particles vibrate on the spot.
- As the particles in ice gain energy, they vibrate more and more.
- This happens until eventually bonds between the particles begin to break. This is called melting.
- The particles start to move about as a liquid.
What temperature does water boil at?
100 ºC
What do we call it when a gas turns into a liquid?
Condensation
What is boiling?
When a substance is changing from a liquid to a gas state (evaporates) at its fastest rate
How do we make a substance boil?
We need to give enough thermal energy (heat) to its particles.
If the temperature of a gas falls below its boiling point, what will happen?
It will condense back into a liquid
What is evaporation?
When some particles in a liquid gain enough energy to escape from its surface. This is different to boiling!
What is the difference between boiling and evaporation?
Evaporation happens at any temperature boiling happens only at the boiling point.
Evaporation is where particles escape from the surface of a liquid, boiling is where gas bubbles form throughout the liquid , rise and then escape,
Use ideas about particles and evaporation to explain why sweating cools you down.
- Sweat comes out of the pores in your skin.
- Water from the sweat evaporates.
- The water particles need energy to move away as a gas.
- They take this energy from your skin, which cools you down.
