States of Matter and State Changes

Ice is the solid state of water, which exists at or below 0 degrees Celsius. For ice to begin melting into liquid water, the temperature must rise above this freezing point.

Condensation is the process where a gas cools down and changes into a liquid. During this phase change, the particles lose thermal energy, slow down, and move closer together.

When you exhale, warm and moist air from your lungs meets the cold outside air. The water vapor in your breath rapidly cools and condenses into tiny liquid water droplets, which appear as a visible mist.

Water in the oceans absorbs heat energy from the sun and changes from a liquid state into water vapor, which is a gas. This process of a liquid turning into a gas at its surface is called evaporation.

Clouds form when rising water vapor cools down high in the atmosphere and changes back into tiny liquid water droplets or ice crystals. This transition from gas to liquid is known as condensation.

Boiling is a rapid phase transition from liquid to gas that occurs throughout the liquid. During this process, the particles absorb heat energy, move faster, and eventually gain enough kinetic energy to overcome the attractive forces holding them together as a liquid.

Pure water freezes into ice at 0 degrees Celsius (0 degrees C) under standard atmospheric pressure. This is also the temperature at which ice melts back into liquid water.

Warm, moist air from the shower comes into contact with the cold surface of the window. This causes the water vapor in the air to cool down and turn back into liquid water droplets on the glass, which is called condensation.

When wet clothes dry, the liquid water trapped in the fabric absorbs heat from the surrounding air and sun, turning into water vapor (a gas) and escaping into the air. This process is called evaporation.

Under standard atmospheric pressure, pure water boils and turns into steam at exactly 100 degrees Celsius (100 degrees C).

Boiling is a physical change where a liquid turns into a gas throughout the entire volume of the liquid, not just at the surface. This rapid phase change causes bubbles of vapor to form within the liquid and rise to the top.

Evaporation is the process where a substance in a liquid state changes into a gaseous state. Condensation is the reverse process (gas to liquid), and solidification is liquid to solid.

Solidifying (or freezing) is the phase transition in which a liquid turns into a solid when its temperature is lowered below its freezing point. Melting is the opposite process, where a solid becomes a liquid.

When a solid melts into a liquid, it absorbs thermal energy from its surroundings. This causes the particles to gain kinetic energy, vibrate more rapidly, and eventually break free from their fixed positions.

Melting is the physical process where a solid absorbs heat and transitions into a liquid state. Freezing and solidifying refer to the reverse process of a liquid becoming a solid.