The fundamental ideas in chemistry

Atoms

• all substances are made of atoms
• an element is something that is made of only one type of atom
• 100 different elements
• groups of periodic table contain elements with similar properties
• protons have positive charge, electrons have negative charge
• number of electrons = number of protons
• atoms have no overall charge
• all atoms of a particular element have the same number of protons
• electrons occupy the lowest available energy levels (innermost available shells)

The periodic table

• group 1 elements react…