Science Vocabulary Unit 3 - Chemical Processes and Equations

Physical Property

A property of a substance that can be observed or measured without changing the substance's identity.
Ex: Density, melting point, boiling point, color, texture, odor, solubility, malleability, and conductivity.

Chemical Property

A property of a substance that define the ways a substance can undergo changes that form different substances.
Ex: Flammability and reactivity (oxygen, water, etc.).

Physical Change

A change in which the identity of the substance remains the same before and after the physical change.
Ex: Change in state, cutting wood, and food coloring.

Chemical Change/Reaction

The process in which the building blocks of matter, atoms, are rearranged to produce different substances with different properties than the original.
Ex: Baking soda and vinegar, rust, and burning

Reactants

The original substance or substances in a chemical reaction.

Products

The substance or substances that form in a chemical reaction.

Precipitate

A solid that is produced as a result of a chemical reaction in a solution.

Chemical Formula

A combination of chemical symbols and numbers that represents a single unit of a substance.

Molecule

A specific group of atoms held together by chemical bonds.

Subscript

A number below and to the right of the symbol, shows how many atoms of that element there are.

Chemical Equation

Uses chemical formulas to model what happens in a chemical reaction. It shows how the substances that are reacting change and form the products of the reaction.

Coefficient

A number placed in front of a chemical formula to show how many molecules of the substance are represented in the chemical equation.

Law of Conservation of Matter

States that matter cannot be created or destroyed in ordinary chemical or physical changes.

Change in color, change in odor, appearance of a gas, energy being released (as light or heat), and formation of a precipitate.

5 signs that a chemical reaction has occurred.