Science Glossary: Key Terms for Home Experiments

Introduction

This glossary provides clear definitions for common scientific terms you’ll encounter in our experiments. Terms are organized alphabetically and color-coded by subject area for easy reference.

How to Use This Glossary

  • Terms are listed alphabetically
  • Subject areas are indicated by icons: 🧪 Chemistry 🔬 Biology ⚡ Physics 🌍 Earth Science 🔭 Astronomy 🌱 Environmental Science

A

Absorption (🧪) The process of taking in or soaking up something, such as when a paper towel soaks up water or a plant takes in nutrients.

Acid (🧪) A substance with a pH less than 7 that can react with metals and bases. Common examples include vinegar and lemon juice.

Adhesion (🧪) The tendency of different substances to stick together, like water droplets clinging to a window.

Alkali (🧪) Also called a base; a substance with a pH greater than 7 that can neutralize acids. Common examples include baking soda and soap.

B

Base (🧪) See Alkali.

Beaker (🧪) A cylindrical container with a pouring spout, used for measuring and mixing liquids in experiments.

Biology (🔬) The study of living things and their processes.

Boiling Point (🧪) The temperature at which a liquid turns into a gas. For water, this is 100°C (212°F) at sea level.

C

Catalyst (🧪) A substance that speeds up a chemical reaction without being consumed by it.

Cell (🔬) The smallest unit of life that can function independently.

Chemical Reaction (🧪) A process where substances combine or break apart to form new substances.

Condensation (🧪) The process of a gas turning into a liquid, like water vapor forming droplets on a cold glass.

D

Density (⚡) The mass of a substance per unit volume, determining whether it will float or sink in other substances.

Diffusion (🔬) The movement of particles from an area of high concentration to an area of low concentration.

Dissolve (🧪) When a substance breaks down in a liquid to form a solution.

E

Ecosystem (🌱) A community of living organisms interacting with their physical environment.

Element (🧪) A pure substance that cannot be broken down into simpler substances through chemical means.

Evaporation (🧪) The process of a liquid turning into a gas at temperatures below its boiling point.

F

Force (⚡) A push or pull that can cause an object to start moving, stop moving, or change direction.

Friction (⚡) The resistance force between two surfaces that are moving against each other.

Freezing Point (🧪) The temperature at which a liquid turns into a solid. For water, this is 0°C (32°F).

G

Gravity (⚡) The force that attracts objects toward each other, particularly the force that attracts objects toward the center of the Earth.

H

Hypothesis (All Sciences) An educated guess or prediction about what will happen in an experiment, based on observations and research.

I

Inertia (⚡) The tendency of an object to resist changes in its motion.

Insulator (⚡) A material that does not easily allow heat or electricity to pass through it.

M

Mass (⚡) The amount of matter in an object.

Mixture (🧪) A combination of two or more substances where no chemical reaction occurs.

N

Neutral (🧪) Having a pH of 7, neither acidic nor basic.

O

Observation (All Sciences) Information gathered by using the senses or scientific instruments.

Oxidation (🧪) A chemical reaction where a substance combines with oxygen, such as when metal rusts.

P

pH Scale (🧪) A scale from 0 to 14 that measures how acidic or basic a substance is.

Photosynthesis (🔬) The process by which plants use sunlight to make food from carbon dioxide and water.

R

Reaction (🧪) See Chemical Reaction.

S

Solute (🧪) The substance that dissolves in a solution.

Solution (🧪) A mixture where one substance (solute) is dissolved in another substance (solvent).

Solvent (🧪) The substance that dissolves another substance in a solution.

T

Temperature (⚡) A measure of how hot or cold something is, based on the movement of its particles.

V

Variable (All Sciences) A factor that can be changed in an experiment.

Volume (⚡) The amount of space that something occupies.

Tips for Using Scientific Terms

  • Always refer back to this glossary when you encounter unfamiliar terms
  • Use proper scientific terminology in your experiment notes
  • Understanding these terms will help you follow experiment instructions more accurately
  • Many terms are related to each other; look for connections between definitions

[Note: This glossary is regularly updated as new experiments are added to our collection.]