Internal energy and changes of state Flashcards
1
Q
What is internal energy?
A
- Total energy in kinetic and potential energy stores
2
Q
Where is internal energy stored?
A
- By particles that make up system
3
Q
How does increasing the temperature affect a substance internal energy?
A
- Increase internal energy
4
Q
What happens when you heat the system?
A
- Transfers energy to particles
- Kinetic energy store increase –> particles move faster
- Potential energy increases
5
Q
What does the size of the temperature or state change depend on?
A
- Mass
- What is it made up of (specific heat capacity)
- Energy input
6
Q
When does a change in state occur?
A
- Substance heated enough
- Energy in kinetic energy store breaks bond
7
Q
How else can changes in state occur?
A
- Cooling
8
Q
What are these cooling changes of state?
A
- Freezing
- Sublimation
- Condesing
9
Q
What is a change of state?
A
- Physical change
- Same substance, different form
10
Q
What happens if you reverse a change of states?
A
- Goes back to original form
- With original properties
11
Q
What is meant by “mass is conserved”?
A
- Number of particles stay the same
- Arranged differently
12
Q
In terms of particles, why does a gas exert pressure?
A
- Pressure on gas surface –> caused by particles repeatedly hitting surface
