Chemical Reactions

Science

The minimum energy needed to start a chemical reaction

Activation energy

The minimum energy needed to start a chemical reaction is called activation energy. Activation energy is like the initial push needed to start a chemical reaction.

A substance that speeds up a chemical reaction by reducing the activation energy

Catalyst

A substance that speeds up a chemical reaction by reducing the activation energy is called a catalyst. A catalyst makes a chemical reaction happen faster without being used up in the process.

A chemical reaction written using element symbols and chemical formulas

Chemical equation

A chemical reaction written using element symbols and chemical formulas is a chemical equation. A chemical equation shows how substances react together to form new substances.

A property that is not visible until a substance undergoes a chemical reaction, like solubility

Chemical property

A property that is not visible until a substance undergoes a chemical reaction, like solubility. Chemical property. A chemical property describes a substance's ability to change into a new substance through a chemical reaction.

A number placed in front of a symbol or formula in a chemical equation

Coefficient

A number placed in front of a symbol or formula in a chemical equation. Coefficient. In Science, a coefficient is a number that shows how many molecules or atoms are involved in a chemical reaction.

The burning of a fuel, where it reacts with oxygen to create heat and light

Combustion

The burning of a fuel, where it reacts with oxygen to create heat and light. Combustion is a chemical process where a substance combines with oxygen to release energy in the form of heat and light.

The chemical breakdown of a substance into simpler substances

Decomposition

The chemical breakdown of a substance into simpler substances. Decomposition is when complex materials break down into simpler parts, like a fallen leaf rotting into soil nutrients.

A heat-absorbing chemical reaction, like ice melting

Endothermic reaction

A heat-absorbing chemical reaction, like ice melting. Endothermic reaction. An endothermic reaction is a process where heat is absorbed from the surroundings.

A protein that speeds up a chemical reaction but remains unchanged itself

Enzyme

A protein that speeds up a chemical reaction but remains unchanged itself. Enzyme. Enzymes are biological molecules that act as catalysts to help speed up chemical reactions in living organisms.

A heat-releasing chemical reaction, like burning or combustion

Exothermic reaction

A heat-releasing chemical reaction, like burning or combustion. Exothermic reaction. It is a type of reaction that releases energy in the form of heat.

A substance that slows down a chemical reaction

Inhibitor

A substance that slows down a chemical reaction. Inhibitor. An inhibitor is a substance that decreases the rate of a chemical reaction.

States that mass cannot be created or destroyed in a chemical reaction

Law of conservation of mass

States that mass cannot be created or destroyed in a chemical reaction. Law of conservation of mass. This means that the amount of matter stays the same before and after a chemical reaction.

A solid formed when two solutions react

Precipitate

A solid formed when two solutions react. Precipitate. A precipitate is a solid that forms and separates from a solution during a chemical reaction.

A new substance formed by a chemical reaction

Product

A new substance formed by a chemical reaction. Product. In science, a product is what you get after substances react and change into something new.

A substance that is changed in a chemical reaction

Reactant

A substance that is changed in a chemical reaction. Reactant. A reactant is a starting material in a chemical reaction that undergoes change to form products.

A reaction that forms a new compound

Synthesis

A reaction that forms a new compound. Synthesis. Synthesis is when two or more substances combine to make a new, more complex substance.