Washington Comprehensive Assessment of Science (WCAS) Grade 5 key terms

Anything that has mass and takes up space. Solids, liquids, and gases are all made of matter, and it can be described by properties such as color, hardness, and weight.

The amount of matter in an object. Mass stays the same even if the object's shape changes or it is moved to a different place.

A measure of how strongly gravity pulls on an object. Weight can change when the pull of gravity changes, such as on the Moon.

A characteristic used to describe or identify a material, such as color, texture, hardness, or whether it conducts electricity. Scientists compare properties to sort and identify substances.

The forms matter can take, usually solid, liquid, and gas. Each state has its own pattern of how particles are packed and move.

A state of matter that keeps its own shape and volume. The particles are packed closely together and vibrate in place.

A state of matter that has a definite volume but takes the shape of its container. Its particles are close but can slide past one another.

A state of matter that has no definite shape or volume and spreads to fill its container. Its particles move freely and are far apart.

The change of a liquid into a gas, which happens at the surface when particles gain enough energy. Puddles dry up because water evaporates into the air.

The change of a gas into a liquid when it cools. Water droplets forming on a cold glass are an example of condensation.

Two or more materials combined without chemically joining, so each keeps its own properties. A mixture can often be separated by physical means such as filtering or sorting.

A mixture in which one material dissolves evenly into another, such as salt in water. The dissolved material is spread throughout and does not settle out.

To break apart and spread evenly through a liquid so that no separate pieces can be seen. Stirring and warming can make some materials dissolve faster.

A push or a pull on an object. A force can start an object moving, stop it, slow it down, or change its direction.

A change in an object's position over time. Motion can be described by how fast and in what direction an object moves.

How far an object travels in a certain amount of time. A faster object covers more distance in the same time than a slower one.

A force that resists motion when two surfaces rub together. Friction can slow moving objects and produce heat.

A force that pulls objects toward each other, especially toward Earth. Gravity makes dropped objects fall and keeps planets in orbit around the Sun.

The ability to cause change or do work. Energy can make things move, heat them up, or produce light and sound, and it can change from one form to another.

The energy an object has because it is moving. A moving ball or a flowing river has kinetic energy.

Stored energy an object has because of its position or condition, such as a ball held high above the ground. It can become motion energy when released.

The movement of energy from one object or place to another, such as heat moving from a warm cup into cooler air. Energy is not lost but moves or changes form.

The transfer of thermal energy from a warmer object to a cooler one. Heat always flows from warmer to cooler until both reach the same temperature.

A measure of how warm or cool something is, related to how fast its particles move. Particles that move faster have a higher temperature.

A form of energy that travels in straight lines and lets us see objects. Light can be reflected, absorbed, or pass through materials.

The bouncing of light off a surface. A mirror reflects light so you can see an image of yourself.

A form of energy that comes from the movement of charged particles. It can flow through a closed circuit to light bulbs, run motors, and power devices.

A complete, closed path that electricity can flow through. If the path is broken, the current stops and devices in the circuit will not work.

A material that allows electricity or heat to pass through it easily, such as copper or aluminum. Metals are usually good conductors.

A living thing, such as a plant, animal, fungus, or bacterium. Organisms grow, use energy, respond to their surroundings, and reproduce.

All the living and nonliving things in a place and the ways they interact. An ecosystem includes organisms, water, soil, air, and sunlight.

The place where an organism lives and finds the food, water, shelter, and space it needs. Different organisms are suited to different habitats.

A model showing the path of energy from one organism to another, starting with a producer and ending with a consumer or decomposer. Arrows show the direction energy flows.

A model of several overlapping food chains that shows how energy moves among many organisms in an ecosystem. It shows that most organisms eat more than one kind of food.

An organism that makes its own food using energy from sunlight, usually through photosynthesis. Plants and algae are producers and form the base of food chains.

An organism that gets its energy by eating other organisms. Animals, fungi, and many bacteria are consumers.

An organism that breaks down dead plants and animals and recycles their nutrients back into the ecosystem. Fungi and many bacteria are decomposers.

The process by which plants use sunlight, water, and carbon dioxide to make their own food and release oxygen. It is how energy from the Sun enters most food chains.

A body part or behavior that helps an organism survive in its environment, such as thick fur in cold places or a beak shaped for cracking seeds.

A characteristic of an organism, such as eye color, fur pattern, or flower color. Traits are passed from parents to offspring through inherited information.

A trait that offspring receive from their parents through genetic information, such as the color of a puppy's fur.

The stages an organism goes through from the beginning of life to adulthood and reproduction. Plants and animals have different but repeating life cycles.

The spinning of Earth on its axis, which takes about 24 hours. Rotation causes day and night as different parts of Earth face the Sun.

The movement of Earth in its orbit around the Sun, which takes about one year. Revolution, along with the tilt of Earth's axis, causes the seasons.

An imaginary line through the center of Earth around which it rotates. Earth's axis is tilted, which helps cause the seasons.

The continuous movement of water between Earth's surface and the air through evaporation, condensation, precipitation, and collection. The Sun provides the energy that drives it.

Water that falls from clouds to Earth's surface as rain, snow, sleet, or hail. It is a key part of the water cycle.

The condition of the air and sky in a place at a certain time, including temperature, wind, clouds, and precipitation. Weather can change from day to day.

The usual pattern of weather in a place over many years. Climate depends on location, and it changes slowly compared with daily weather.

The carrying away of weathered rock and soil by water, wind, or ice. Erosion slowly changes the shape of landforms such as hills and riverbanks.

The breaking down of rock into smaller pieces by water, wind, ice, or living things. Weathering happens in place and prepares material for erosion.

The dropping of eroded rock, sand, or soil in a new place. Deposition builds up landforms such as deltas and sand dunes.

The preserved remains or traces of a living thing from long ago, usually found in rock. Fossils give evidence about organisms and environments of the past.

Rock formed from layers of sand, mud, or other materials that pile up and harden over time. Many fossils are found in sedimentary rock.

Something from nature that living things use, such as water, soil, wood, or minerals. Some resources are renewable and some are limited.

A natural resource that can be replaced or replenished in a reasonable amount of time, such as sunlight, wind, or trees that are replanted.

The substances that make up Earth, including rock, soil, water, and air. People use these materials for building, growing food, and many other needs.