Science Glossary

131 unique terms across the 29 rooms.

abiotic factor

A nonliving physical or chemical part of an ecosystem.

abundance

How many organisms are present in a defined place or sample.

atmosphere

The mixture of gases surrounding Earth.

atom

The smallest unit of an element that keeps that element’s identity.

atom count

The number of atoms of each element represented in a model.

biodiversity

The variety of life at genetic, species, and ecosystem levels.

biotic factor

A living part of an ecosystem.

carbon cycle

The movement of carbon among Earth’s living and nonliving systems.

carbon dioxide

A molecule made of one carbon atom and two oxygen atoms.

carrying capacity

A model of the population size an environment can support over time.

cellular respiration

A set of reactions that releases stored energy from food molecules.

chemical reaction

A process in which atoms are rearranged into new substances.

chloroplast

A structure in plant and algal cells where photosynthesis occurs.

closed system

A system in which matter does not cross the chosen boundary.

competition

An interaction in which organisms seek the same limited resource.

composition

The kinds and amounts of matter that make up a substance.

condensation

Change of water vapor to liquid water.

conservation of matter

The principle that matter is not created or destroyed in ordinary physical and chemical changes.

constraint

A limit on a design, such as time, cost, materials, or safety.

constraints

Plural of constraint: limits that shape a design.

consumer

An organism that gets matter and energy by eating other organisms.

continental shelf

The gently sloping submerged edge of a continent.

correlation

A pattern in which two variables change together; it does not by itself prove cause.

criteria

Plural of criterion: requirements used to judge a design.

criterion

A requirement used to judge whether a design succeeds.

crystallization

Formation and growth of an ordered solid structure.

cycle

A set of processes that returns matter to earlier locations or forms.

decomposer

An organism that breaks down dead matter and returns materials to the environment.

density

The amount of mass in a given volume.

deposition

The settling or placement of transported sediment.

design solution

A proposed object, process, or system intended to meet a need.

distribution

How something is arranged or spread across an area.

disturbance

An event that changes ecosystem conditions or structure.

ecosystem service

A benefit people receive from functioning ecosystems.

electron

A negatively charged particle found around an atom’s nucleus.

element

A pure substance made of only one kind of atom.

empirical evidence

Information gathered through observation or measurement.

energy flow

One-way transfer of energy through parts of a system.

energy transfer

Movement of energy from one object or system to another.

erosion

The movement of weathered material by water, wind, ice, or gravity.

evaporation

Change of liquid water to water vapor.

evidence

Information used to support or challenge a claim.

extended structure

A repeating arrangement of atoms or subunits that continues through a material.

fault

A break in rock along which movement has occurred.

floodplain

Low land beside a river that may be covered by floodwater.

food web

A model of connected feeding relationships in an ecosystem.

forecast

A statement about the likelihood or location of future conditions based on evidence.

fossil

Preserved evidence of past life.

gas

A state of matter that expands to fill its container.

geosphere

Earth’s solid rock, sediment, soil, and interior.

glucose

A sugar molecule that stores chemical energy.

groundwater

Water stored and moving beneath Earth’s surface.

habitat

The place and conditions in which an organism lives.

hazard

A natural process or condition that can cause harm.

hydrosphere

All of Earth’s water in liquid, solid, and gas forms.

igneous

Rock formed when molten material cools and solidifies.

indicator

A measured sign used to infer the state of a system.

inference

A logical interpretation based on evidence and reasoning.

infiltration

Movement of water from the ground surface into soil or rock.

iteration

A cycle of testing, learning, and revising.

kinetic energy

Energy an object or particle has because it is moving.

life cycle

The linked stages of a product from resources through manufacture, use, and end of life.

limiting factor

A condition or resource that restricts growth, survival, or population size.

liquid

A state of matter with a stable volume that takes the shape of its container.

magnitude

A measured size or strength of an event.

mass

A measure of the amount of matter in an object or system.

mass wasting

Downslope movement of rock or soil caused mainly by gravity.

matter

Anything that has mass and takes up space.

melting point

The temperature at which solid and liquid states can coexist under stated pressure.

metamorphic

Rock changed by heat, pressure, or fluids without fully melting.

mineral deposit

A concentration of useful minerals formed by geologic processes.

mitigation

Action taken to reduce the effects of a hazard.

model

A purposeful representation used to explain, test, or predict.

molecule

Two or more atoms joined in a specific arrangement.

mutualism

An interaction in which both participating species benefit.

natural resource

Matter or energy from Earth systems that people use.

nonrenewable

Not replaced on a human time scale as quickly as it is used.

nucleus

The dense center of an atom, containing protons and neutrons.

optimization

Improving a design across stated criteria and constraints.

particle model

A representation that explains matter using tiny moving particles.

particle motion

Movement of atoms or molecules in matter.

phase change

A change between solid, liquid, and gas states.

photosynthesis

A process that uses light energy to make sugars from carbon dioxide and water.

plate boundary

A region where two tectonic plates meet.

plate motion

Movement of a section of Earth’s rigid outer layer.

population

All individuals of one species living in a defined area.

population shift

A change in the size, location, or composition of a population.

precipitation

Water that falls from the atmosphere as rain, snow, sleet, or hail.

predation

An interaction in which one organism captures and eats another.

probability

A number or description of how likely an event is.

producer

An organism that makes its own food, usually using light energy.

product

A substance formed by a chemical reaction.

property

An observable or measurable characteristic of matter.

proton

A positively charged particle in an atom’s nucleus.

reactant

A starting substance in a chemical reaction.

rearrange

To change the positions or connections of parts without making the parts vanish.

rearrangement

A change in how existing parts are organized or connected.

relative age

Whether an event or rock is older or younger than another, without assigning a number.

reservoir

A place where matter is stored for some period of time.

resilience

A system’s ability to absorb change and continue functioning or recover.

resource

Something an organism needs, such as food, water, light, oxygen, or space.

restoration

Assisting the recovery of a damaged or changed ecosystem.

risk

The combination of hazard likelihood, exposure, and possible consequences.

rock cycle

The linked processes that transform Earth materials among rock types.

scale

The size, distance, amount, or time range used to study a phenomenon.

seafloor

The solid surface beneath ocean water.

seafloor spreading

Formation of new ocean crust at a mid-ocean ridge.

sedimentary

Rock formed from deposited sediment or precipitated material.

solid

A state of matter with a stable shape and volume under ordinary conditions.

solubility

How much of a substance can dissolve under stated conditions.

species richness

The number of different species in a defined area or sample.

stored energy

Energy held in a system and available for later transfer or change.

stratum

One layer of sediment or sedimentary rock; plural: strata.

subduction

A process in which one tectonic plate moves beneath another.

substance

Matter with a characteristic composition and set of properties.

subunit

A smaller repeating part of a larger structure.

synthetic material

A material made through human-directed chemical processes.

system

A set of interacting parts with a defined boundary.

tectonic plate

A large, moving piece of Earth’s rigid outer layer.

temperature

A measure related to the average kinetic energy of particles.

thermal energy

Internal energy related to particle motion and interactions.

trade-off

A choice in which improving one outcome may reduce another.

transfer

Movement of matter or energy from one part of a system to another.

trophic level

A feeding position in a food chain or web.

tsunami

A series of large waves caused by sudden displacement of water.

uplift

Upward movement of Earth’s crust.

warning system

People, sensors, communication, and procedures that alert a community to danger.

water cycle

The movement of water through the atmosphere, land, oceans, and living things.

water purification

Removal or breakdown of substances that reduce water quality.

watershed

Land area that drains water to a common outlet.

weathering

The breakdown or chemical change of rock at or near Earth’s surface.