molecules as groups of atoms

So every different material is made from different substances. This is just like words, there are millions of words in the english language, but they are all made up from the same 26 letters, just arranged in certain manners. So too it is with different materials these materials are made of very similiar atoms but organised in different ways. When we have two or more atoms joined together we call this a molecule.

There are millions of different atoms, a list here, note most of these you will come across in your science studies, notice how many molecules contain similar atoms

Calcium Carbonate (CaCO3) Calcium Hydroxide (Ca(OH)2) Carbon Dioxide (CO2)

Copper Sulphate (CuSO4) Calcium Ion (Ca2+) Calcium Hydrogen Carbonate (Ca(HCO3)2)

Magnesium Ion (Mg2+) Magnesium Sulphate (MgSO4) Magnesium Hydrogen Carbonate (Mg(HCO3)2)

Calcium Sulphate (CaSO4) Water (H2O) Hydrogen Oxide (H2O) Sulphuric Acid (H2SO4)

Hydrochloric Acid: (HCl) Sodium Hydroxide (NaOH) Hydrogen Peroxide (H2O2 )

Manganese Dioxide (MnO2) Calcium Chloride (CaCl2) Methane (CH4) Rust (Fe2O3.3 H2O)

Oxygen (O2) Sulphur Dioxide (SO2)

Many Molecules are sometimes called Compounds

Some 3d molecules can be found here