The Periodic Table

Worked examples (3)

• 1Electron shells and outer electrons from position in periodic table
• 2Why elements in the same group have similar chemical properties
• 3Significance of Mendeleev's gaps

Worked examples (3)

• 1Atomic radius trend across Period 3
• 2Ionisation energy trend down Group I
• 3Reactivity trend down Group VII

Worked examples (4)

• 1Reaction of potassium with water
• 2Why potassium is more reactive than sodium with water
• 3Halogen displacement — chlorine and potassium iodide
• 4Why chlorine is a gas but iodine is a solid at room temperature

Worked examples (3)

• 1Properties of transition metals vs Group I
• 2Variable oxidation states explained
• 3Iron catalyst in the Haber process

Worked examples (3)

• 1Why noble gases are unreactive
• 2Helium vs hydrogen in balloons
• 3Why argon is used in light bulbs