Section 1 principles of chemistry (1.1, 1.2 1.3)
States of matter
Solid
Liquid
Gas
Arrangement
Spacing
Movement
Regular repeating
pattern (lattice)
Close together and
touching
Vibrate about fixed
positions
Attractive forces
strong
Definite shape and
volume
Effect of heating
Particles vibrate
more and sold
expands slightly
irregular
Close together and
touching
Move around and
slide past one
another (flow)
weak
Definite volume but
not shape (will flow
to fill the bottom
of container)
Particles move
faster and liquid
expands slightly
when heated
irregular
Far apart
Move freely and
randomly in straight
lines and constantly
collide with one
another
Very weak
No definite shape
or volume and fill
any container
Particles move
faster and gases
expand (if space
allows) or pressure
increases.
Changes of State blue arrows = heat energy given out red arrows = heat energy taken
in
Solid
Liquid
When solids are heated particles gain more energy so they vibrate more which weakens
the bonds holding them together. The solid expands.
At melting point the particles have enough energy to break free from their positions
and the solid melts into a liquid.
Liquid
Gas
When liquids are heated the particles gain more energy so particles move even faster
which weakens and breaks the bonds holding the liquid together.
At boiling point particles have enough energy to break their bonds and the liquid
evaporates into a gas.
Solid
Liquid
Gas
Heating
* Particles gain energy
* vibrate more, bonds
weaken
* solid expands
* melting pt - solid
becomes liquid
* Particles gain energy
* move fast, bonds break
* boiling pt- bonds broken
and particles evaporate
* particles gain energy
* move faster
* take up more volume OR
increased pressure
Cooling
*particles lose energy
* Vibrate less
*solid contracts
* Particles lose energy
* Move more slowly
* freezing pt - bonds form
and liquid solidifies
* Particles lose energy
* Move more slowly
* Condensation pt - Weak
bonds form and gas
condenses
Questions
State whether liquid, solid or gas;
1. A substance changes shape and volume according to its container; ______________
2. A substance changes neither shape or volume; ________________
3. A substance does not change volume but does changes shape according to its
container; _________________________
4. Which state has the strongest forces of attraction? _______________
5. Which state has the weakest forces of attraction?_________________
6. Describe what happens to the energy, movement and attractive forces of gas
particles at condensation point.
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7. Describe what happens to the energy. movement and attractive forces of liquid
particles at freezing point.
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8. Describe the changes in energy, movement and attractive forces when a liquid turns
into a gas.
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9. Describe the changes in energy, movement and attractive forces when a solid turns
into liquid.
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