Unit 4 - elements, compounds, mixtures

Element

A pure substance made up of only one type of atom

Compound

A pure substance made of two or more elements chemically joined together

Mixture

A combination of two or more substances that are mixed together but not chemically joined. Mixtures can be separated using techniques such as filtration

Atom

Smallest particle of an element and is the basic building block in chemistry

Molecule

A groups of two or more atoms chemically bonded together

Proton

A subatomic particle that has a positive charge, a relative mass of 1 and that is found in the nucleus of an atom

Neutron

A subatomic particle that has no charge, a relative mass of 1 and that is found in the nucleus of an atom

Electron

A subatomic particle that has a negative charge, a relative mass of nearly 0 and are found in electron shells surrounding the nucleus of an atom

Chemical change

A change in matter that produces one or more new substances, with different properties to the reactants

Reactants

The elements or compounds that enter into a chemical reaction

Products

The elements or compounds produced by a chemical reaction that are formed from the reactants

Conservation of mass

The principle stating that matter is not created or destroyed during a chemical reaction

Heterogeneous mixtures

A mixture in which different materials are in separate layers and can be distinguished easily

Homogenous mixtures

A mixture that is the same throughout

Solution

A homogeneous mixture that forms when one substance dissolves into another substance

Solvent

A liquid substance capable of dissolving other substances (eg. water in the solution of salt and water)

Solute

A soluble substance that is dissolved in a solution (eg. salt in the solution of salt and water)

Soluable

A substance which can dissolve (eg. salt, sugar, baking soda)

Insoluable

A substance that cannot dissolve

Solubility

The amount of solute that can dissolve in a given amount of solvent at a given temperature

Dilute solution

A solution that contains a small amount of solute and is capable of dissolving more solute

Concentrated solution

a solution containing a large amount of solute and is capable of dissolving a little more solute

Saturated solution

A solution that has the maximum amount of solute in it and cannot dissolve any more solute under the given conditions