Y10 Chemistry

Independent variable

A variable that the chemist changes.

Dependent variable

A variable that the chemist measures.

Control variable

A variable the chemist has to make sure to keep the same.

Solute

A substance dissolved in the solvent.

Solvent

The substance the solute is dissolved in.

Mixture

The end product of both mixtures.

Soluble

Able to dissolve.

Insoluble

Unable to dissolve.

Simple distillation

Used to separate the solvent from a solution.

How simple distillation is used

The heated solvent evaporates, leaving the solute behind due to the solute's higher boiling point.

Filtration

Used when the solute is insoluble.

How filtration works

Filtration works by passing the mixture through a filter.

Crystallization

Used when in need of purifying a solid such as soluble salt.

How crystallization works

It dissolves the mixture/solid and slowly evaporates it, forming crystals.

Paper chromatography

Used to separate mixtures and to help identify the substances.

How chromatography is used

Different colors spread on paper, and as water moves, it pushes the color further to identify its Rf value.

Solubility of a substance

Defined by how far the substance travels on the chromatography sheet.

How the Rf value is defined

The Rf value is defined by dividing the travel of the substance by the length of the paper.

Atoms

The basic units that make up all matter.

Molecule

Formed when atoms chemically join and form bonds.

Element

A substance made up of a single type of atom.

Compound

A substance made up of different types of atoms.

Mixture

Two or more atoms NOT chemically bonded together.

Pure substance

An element that boils/melts at a specific temperature.

Atomic mass

The number of protons in an atom.

Atomic mass (total)

The number of both protons and neutrons in an atom.

Isotope

An element that has the same number of protons but different numbers of neutrons.

Relative atomic mass

The weighted average of an atom.

Period group

Atoms with the same number of electrons in the outer shell, giving them similar chemical properties.

Metals

Conductive elements that react to form positive ions.

Non-metals

Non-conductive elements that react to produce negative ions.

The Law of conservation of mass

States that no matter is gained or lost in a chemical reaction.