10) Changing States

What happens to particles when a solid is heated?

Particles gain energy, vibrate more, and weaken the forces holding the solid together.

What is the melting point?

The temperature at which particles gain enough energy to break free from their fixed positions, turning a solid into a liquid.

What is freezing?

The process of a liquid losing energy and forming bonds between particles, turning back into a solid.

What happens when a liquid is heated?

The particles gain energy, move faster, and weaken the bonds holding the liquid together.

What is the boiling point?

The temperature at which particles have enough energy to break their bonds and transition from liquid to gas.

What is condensing?

The process where a gas cools, losing energy, and forms bonds between particles, turning back into a liquid.

How does energy affect state changes?

The energy required for a state change depends on the strength of forces between particles; stronger forces need more energy, resulting in higher melting and boiling points.

How can you predict the state of a substance at a certain temperature?

If the temperature is below the melting point, it's a solid; if above the boiling point, it's a gas; and if between, it's a liquid.

At what temperature is bromine a liquid?

Bromine is a liquid at room temperature (25 °C) because it melts at -7 °C and boils at 59 °C.

What are the melting and boiling points for oxygen?

Oxygen has a melting point of -219 °C and a boiling point of -183 °C.