Unit 1: Principles of Chemistry

What are all substances made of?

Tiny particles (atoms, molecules or ions)

What causes the differences between solids, liquids and gases?

Arrangement, movement and energy of particles

What are the three factors that differ in the states of matter?

Arrangement, movement and energy of particles

What shape does a solid have?

Fixed shape

What volume does a solid have?

Fixed volume

Can solids be compressed easily?

No

How are particles arranged in a solid?

Closely packed in a regular arrangement

What type of forces are present in solids?

Strong forces of attraction

How do particles move in a solid?

They vibrate about fixed positions

What type of kinetic energy do solids have?

Lowest kinetic energy

What volume does a liquid have?

Fixed volume

What shape does a liquid have?

No fixed shape, takes shape of container

Are liquids easily compressed?

No, they are hardly compressible

How are particles arranged in a liquid?

Close together in a random arrangement

How do particles move in a liquid?

They move and slide past each other

How does the kinetic energy of liquids compare to solids?

Liquids have more kinetic energy than solids

Does a gas have a fixed shape?

No

Does a gas have a fixed volume?

No

Are gases easily compressed?

Yes

How are particles arranged in a gas?

Far apart in a random arrangement

How do particles move in a gas?

Rapid random motion in all directions

Which state has the highest kinetic energy?

Gas

Which state has the lowest kinetic energy?

Solid

Which state has medium kinetic energy?

Liquid

What shape does a liquid take?

The shape of its container

What shape does a gas take?

It fills the container

Which state is easiest to compress?

Gas

Which state is hardest to compress?

Solid

Describe particle movement in solids.

Vibrate only

Describe particle movement in liquids.

Slide past each other

Describe particle movement in gases.

Rapid random movement

Describe the arrangement of particles in solids.

Regular and close together

Describe the arrangement of particles in liquids.

Random and close together

Describe the arrangement of particles in gases.

Random and far apart

What happens to particle spacing from solid to gas?

Particles become further apart

Why do solids keep their shape?

Particles are held in fixed positions by strong forces

Why can liquids flow?

Particles can slide past each other

Why are gases easily compressed?

Particles are far apart with large empty spaces

What is the change from solid to liquid called?

Melting

What is the change from liquid to solid called?

Freezing

What is the change from liquid to gas called?

Boiling / Evaporation

What is the change from gas to liquid called?

Condensation

What is the change from solid to gas called?

Sublimation

What is the change from gas to solid called?

Deposition

What does heating do to particles?

Gives particles more kinetic energy

What happens to particles during melting?

Solid particles vibrate faster

What happens to forces during melting?

Forces weaken

What happens to particles after melting?

Particles can move past each other

What happens during boiling or evaporation?

Liquid particles gain enough energy to escape

How are gas particles arranged after boiling?

Gas particles spread far apart

What is sublimation?

A solid changes directly into a gas

Give one example of sublimation.

Iodine

Give another example of sublimation.

Dry ice

What does cooling do to particles?

Removes kinetic energy

What happens to gas particles during condensation?

Gas particles lose energy

How do particles move during condensation?

Move slower and come closer together

What happens to liquid particles during freezing?

Liquid particles lose energy

What happens to particles after freezing?

Become fixed in place

What is deposition?

Gas changes directly into solid

What happens to particle arrangement during melting?

Becomes less ordered

What happens to particle movement during melting?

More movement

What happens to energy during melting?

Energy increases

What happens to particle arrangement during boiling?

Particles become far apart

What happens to particle movement during boiling?

Rapid movement

What happens to energy during boiling?

Energy increases

What happens to particle arrangement during freezing?

Becomes more ordered

What happens to particle movement during freezing?

Less movement

What happens to energy during freezing?

Energy decreases

What happens to particle arrangement during condensation?

Particles come closer together

What happens to particle movement during condensation?

Slower movement

What happens to energy during condensation?

Energy decreases

Where does boiling occur?

Throughout the liquid

Where does evaporation occur?

At the surface only

At what temperature does boiling occur?

A fixed temperature

At what temperature can evaporation occur?

Any temperature

Is boiling fast or slow?

Fast

Is evaporation fast or slow?

Slow