Molecules and Ions
Atoms
The atomic sturcture
Nucleus
Neutron
Proton
Electrons
Isotopes
Atoms with identical atomic number but different mass number
Atomic Mass
Weighed average of masses of an element's all naturally occuring isotopes
The periodic table
A table that tells us the symbol, atomic number and atomic mass of elements
Forming compounds
Chemical compounds
Ionic compounds
Ions
Formed when atoms combine together through ionic bonding which atoms can give away or take in electrons to form ions.
Covalent compounds
Moleules
Formed from covalent bonding and it occurs between atoms of non-metals
Classification of Matter
Pure substances
Elements
Made up from atoms of the same kind which is in their simplest form and cannot be broken down further by ordinary means, e.g. oxygen.
Compound
Made up from atoms of different kinds, e.g. water.
Mixtures
Hetrogeneous
Do not have uniform composition, e.g. salad and concrete.
Homogeneous
Uniform composition, solutions, air and ink.