L1 CLASSIFYING MATTER

Lesson one - classifying matter

UNDERSTANDING MATTER

Matter - anything that has mass and takes up space.

Everything around us is matter.

Atoms - a small particle that is a building block of matter.

At the center of the atom is the nucleus.

Protons - positive charge and neutrons - neutral charge make up the nucleus.

Electrons - negative charge, move quickly throughout an area around the nucleus which is called the electron cloud.

NOT ALL ATOMS HAVE THE SAME AMOUNT OF ATOMS, PROTONS, OR ELECTRONS.

Atoms determine the properties of the matter they compose.

SUBSTANCES

There are two main classifications of matter and they are substances and mixtures.

A substance is matter with a composition that always stays the same.

Ex) aluminum, oxygen, sugar and water - they always are made up of the same combinations of atoms.

ELEMENTS

An element is a substance that consists of just one type of atom.

The number of protons in an atom is the atomic number.

COMPOUNDS

A compound is a type of substance containing atoms of two or more different elements chemically bonded together.

Ex) CO₂ (it consists of atoms of two different elements bonded together)

The combination of symbols and numbers that represents a compound is called a chemical formula.

MIXTURES

A mixture is matter that can vary in compostion.

Mixtures can be separated by physical methods because they do not chemically combine together.

A heterogenous mixture is a type of mixture in which the individual substances are not evenly mixed.

A homogenous mixture is a type of mixture in which the individual substances are evenly mixed.

A homogenous mixture is also known as a solution.

In a solution, the substances present in the largest amount is called the solvent. All of the other substances are called solutes.

The solutes dissolve in the solvent.

To dissolve - to form a solution by mixing evenly