Science Study

Atomic number

The number of protons in the nucleus of an atom

Mass number

The total number of protons and neutrons in a nucleus

Protons

Positively charged particle found inside the nucleus of an atom

Nucleus

Central part of an atom that consists of protons and neutrons

Neutrons

A particle found inside the nucleus of an atom, it has no charge ( is neutral)

Electrons

A negatively charged particle fond in electron shells that move around the outside of the nucleus

Element

A substance made up of one kind of atom

Compound

A substance made from two or more different elements that have been chemically joined

Molecule

Two or more atoms chemically joined together

Mixture

A substance made of two or more different chemical substances that are not bonded together

Metal

These elements are located on the left hand side of the periodic table mainly hard, shiny, malleable, heat and electrical conductor e.g coppor

Non-metal

These elements are located on the right hand side of the periodic table, with the exception of hydrogen

Acid

A substance that produces hydrogen ions (H+) when dissolved in water

Base

A substance that accepts hydrogen ions (H+) or that dissolves to release hydroxide ions (OH)

Alkali

A soluble base

Indicator

A substance that undergoes a distinct observable change to indicate if a substance is an acid, a base or neutral e.g. blue and red litmus paper, universal indicator.

Litmus

A piece of paper that changes its colour to indicate if a substance is an acid, base or neutral

Neutralisation

A chemical reaction between an acid and a base which produces a more neutral solution (salt and water)

What colour is strong acid (pH scale)

Red

What colour is weak acid (pH scale)

Orange/Yellow

What colour is strong base (pH scale)

Indigo, Violet

What colour is weak base (pH scale)

Blue

What colour is neutral (pH scale)

Green