Chemistry-C2

Chemistry-C2

Relative formula mass

• Find the atomic mass of each element multiplied by the amount of atoms of thatt element present in the formula, then add them up.
• Calcium sulphate CaSO4

Atoms and Ar- Ca=40  S=32  O=16

so               (40x1) + (32x1) + (16x1) =136

• Atoms and molecules are far too small to be counted, to make this easier, chemists call the atoms or formula mass measured in grams a mole

More complicated formula mass

• Aluminium sulphate Al2(SO4)3

Atoms and Ar-  Al= 27  S=32  O=16

so               (27x2) + (32x3) + (16x12)= 342

Giant Ionic structures

• High melting points-alot of dtrong bonds hard to break
• Doesn't conduct electricty because no free moving electrons, ions can conduct if molten 

Giant Covalent structures

Diamond

• Lustrous (shiny)
• Colourless and clear (transparent)
• Hard
• High melting point
• Insoluble in water (does not dissolve)
• Does not conduct electricity
• Used in jewellery
• Has a giant molecular structure, each carbon is covalently bonded four times, very…