1.1 Atoms, elements and compounds
- All substances are made up of atoms
- Elements are made only of one type of atom.
- Chemical symbols are used to represent atoms.
- Compounds contain more than one element.
1.2 Atomic Structure
- The nucleus of an atom is made of protons and neutrons.
- Protons have a positive charge, electrons a negative charge and neutrons are not charged at all.
- The atomic number of an element is equal to the number of protons in the nucleus of its atoms.
- Elements are arranged in order of their atomic numbers in the periodic table.
- The mass number is the sum of the…