C1 Changing State Flashcards
What do physical changes change?
The arrangement or energy of the particles.
When a solid is heated, what do the particles gain?
More energy
What effect does gaining energy have on the particles, when a solid is heated?
The particles vibrate more, which weakens the forces that hold them together.
At a certain temperature particles have enough energy to break free from their positions. What is this temperature called?
Melting point
What happens to a solid when it reaches melting point?
Turns into a liquid.
What do the particles gain when a liquid is heated?
More energy
What happens to the particles in a liquid when they are heated?
They gain more energy, this makes the particles move faster, which weakens and breaks the bonds holding them together.
What is the name for the temperature at which a liquid becomes a gas?
Boiling point
What happens at boiling point?
The particles have enough energy to break all of their bonds . The liquid becomes a gas.
What happens to the particles as a gas cools?
The particles no longer have enough energy to overcome the forces of attraction between them.
Bonds form between the particles.
What is it called when a gas cools and becomes a liquid?
Condensing
What happens as a liquid cools?
The particles have less energy, so move around less.
What happens to the particles as a liquid becomes a solid?
There’s not enough energy to overcome the attraction between particles, so more bonds form. So many bonds form that the particles are held in place. The liquid has become solid.
What is the name for a liquid becoming a solid?
Freezing
What determines how much energy is required for a substance to change state?
How strong the forces between particles are.
The stronger the forces the more energy is needed to break them, so the higher the melting and boiling points of the substance.
