Materials and Their Structure - States of Matter and the Water Cycle

Vocabulary flashcards covering key scientific terms, definitions, and concepts about states of matter, changes of state, measurement tools, and the water cycle.

Matter

Everything that you can see and feel.

Properties

The specific ways that states of matter behave.

Solids

A state of matter in which particles keep the same shape and volume, and cannot be compressed or poured.

Liquids

A state of matter in which particles take the shape of their container, can be poured, cannot be compressed, and keep a fixed volume.

Gases

A state of matter in which particles flow like liquids, fill any closed container, have variable volume, and are very easy to compress.

Hypothesis

A suggestion for an explanation made by scientists that can be tested by carrying out more investigations.

Theory

An hypothesis that has been tested and widely accepted as valid by other scientists.

Particles

Tiny portions of matter that make up all matter and are arranged in different ways in solids, liquids, and gases.

Particle Theory

The scientific theory stating that all matter is made up of tiny particles that are arranged differently in solids, liquids, and gases.

Measuring Cylinder

A piece of laboratory equipment used to measure the volume of a liquid.

Meniscus

The curve formed by a liquid at the top of a measuring cylinder, measured from the bottom with eye level to it.

Thermometer

An instrument used to measure temperature containing a liquid that expands and rises as it gets hotter.

Evaporation

The process in which liquid water turns into water vapour (a gas) when particles gain enough energy to break free from attractive forces.

Transpiration

The process by which water evaporates into the atmosphere from plants.

Condensation

The process in which water vapour cools and changes back into droplets of liquid water as particles lose energy.

Precipitation

Water falling from clouds to Earth as rain, snow, hail, or sleet when water droplets become too heavy for air to hold.

Melting

The change of state from solid to liquid when a solid is heated and its particles gain enough energy to slide past one another.

Boiling Point of Water

The temperature at $100\,^\circ\text{C}$ at which liquid water rapidly changes into steam (gas).

Freezing

The change of state from liquid to solid as heat energy is transferred away, causing particles to slow down and vibrate in a fixed pattern.

Groundwater

Water from precipitation that soaks into soil and rocks to refill underground stores.

Surface Run-off

Water that reaches the land surface and flows directly across the ground into rivers, lakes, and oceans.

Water Cycle

The continuous system that recycles water on Earth between rivers, lakes, oceans, the atmosphere, and the land.