Forces Between Particles
Chemistry: IB Diploma Higher Level, topic 1.1.5
Melting and Boiling Points - Forces Between Particles
The amount of energy required for substances to change state depends on the strength of the forces between their particles.
Strong forces
- Strong forces between particles means lots of energy is needed to overcome them.
- Substances with strong forces between particles have high melting and boiling points.
Weak forces
- Weak forces between particles means little energy is needed to overcome them.
- Substances with weak forces between particles have low melting and boiling points.
Test yourself on Forces Between Particles
Which of the following is true for a solid with a high melting point?
Sulfur has a melting point of 115°C. What state will it be at 100°C?
Sulfur has a boiling point of 445°C. What state will it be at 444°C?
Chlorine's boiling point is -34°C. What state is chlorine at room temperature (20 - 25°C)?