elements atoms and compounds science

Atoms

An Atom is the smallest part of an element that can exist.

Molecule

A molecule is more then one Atom chemically bonded

Compound

Compounds are made of two or more different atoms strongly joined together

• it can be broken down into other substances.

Elements

An element:

•cannot be broken down into other substances

•It is made up of one type of atom only

Periodic table

The names and symbols of all the elements can be found on the periodic table.

•elements are grouped together by their properties which are different for each element.

•Chemical symbols are universal , it's the same in every language , even if the name of the element is different.

Chemical formulae

A chemical formula tells you the relative number of atoms of each element that is in the compound example:

•H2O = two hydrogen atoms for every oxygen atom.

Naming compounds

In a compound made of metal and non metal the name of the metal comes first example:

• iron bromide , magnesium fluoride

If the non metal atom is oxygen it is called ‘oxide’ .

• If the non metal is chlorine it's called ‘chloride’. Example:

Copper oxide , Sodium chlroride.

In a compound made of a non metal and oxygen , the oxygen comes second and is called monoxide if there is one oxygen atom or dioxide for two oxygen atoms , example:

•carbon monoxide

•sulfure Dioxide