GCSE Pearson Edexcel Separate Science Chemistry: The Periodic Table

Döbereiner's triads

Groups of three elements that share similar properties

Newlands' Law of Octaves

Every eighth element shares common properties

Group 1

Alkali metals

Group 7

Halogens

Group 0

Noble gases

Molecule

A group of atoms bonded together

Halide

A compound formed from a halogen and an element from another group

Monatomic

A single atom

Diatomic

A molecule made of exactly two atoms

Anion

A negatively charged ion

Cation

A positively charged ion

Metalloid

An element that has properties between metals and non-metals

Inert

Chemically inactive or unreactive

Ductile

To have the ability to be drawn out into a thin wire

Symbol for calcium

(Don't forget the capital 'C' and lowercase 'a'!)

Symbol for fluorine

(Make sure you write this as a capital 'F'!)

Formula for sodium chloride

(This needs to be written with a capital 'N' then lowercase 'a', a capital 'C' and a lowercase 'l')

Formula for lithium hydroxide

(Don't forget a capital 'L', a lower case 'i', a capital 'O' and 'H'!)

Formula for potassium sulfide

(Remember - a capital 'K', small '₂' and a capital 'O')

Formula for sodium oxide

(We write this as a capital 'N' and lower case 'a' , a small '₂' and a capital 'O')