Kes notes

• What happens to melting points down Group 2?

  Melting points decrease down the group
• Why do melting points decrease down Group 2?

  Metallic bonding weakens as atomic size increases
• What causes the weakening of attractive forces in Group 2 metals?

  The distance between positive ions and electrons increases
• What happens to atomic radius down Group 2?

  Atomic radius increases down the group
• Why does atomic radius increase down Group 2?

  Atoms have more shells of electrons
• What is the outer shell electron configuration of Group 2 metals?

  s$^2$ electron configuration
• What is the first ionisation energy?

  Energy needed to remove an electron from one mole of gaseous atoms
• What trend occurs in first and second ionisation energies down Group 2?

  Both decrease down the group
• Why do ionisation energies decrease down Group 2?

  Electrons are further from the nucleus and more shielded
• What happens to reactivity of Group 2 metals down the group?

  Reactivity increases down the group
• Why does reactivity increase down Group 2?

  More shielding makes it easier to remove electrons
• What is the second ionisation energy?

  Enthalpy change when one mole of gaseous ions forms another mole of gaseous ions
• What do Group 2 metals lose during redox reactions?

  They lose outer shell s$^2$ electrons
• What does magnesium react with slowly?

  Oxygen without a flame
• What forms on magnesium ribbon when it reacts with oxygen?

  A thin layer of magnesium oxide
• Why must magnesium ribbon be cleaned before reactions?

  To avoid false results in reaction rates
• What is the reaction of magnesium with hydrochloric acid?

  Mg + 2HCl → MgCl₂ + H₂
• What is the reaction of magnesium oxide with hydrochloric acid?

  MgO + 2HCl → MgCl₂ + H₂O
• What do Group 2 metals do when they react with oxygen?

  They burn in oxygen
• What color flame does magnesium produce when burning?

  Bright white flame
• What is the product of magnesium burning in oxygen?

  Magnesium oxide (MgO)
• What is the state of magnesium oxide at room temperature?

  White solid
• Why does magnesium oxide have a high melting point?

  Due to its ionic bonding
• What do magnesium and steam produce when reacted?

  Magnesium oxide and hydrogen
• How does magnesium burn in steam?

  With a bright white flame
• What do other Group 2 metals produce when reacting with cold water?

  Hydroxides and hydrogen
• What observations are made when Group 2 metals react with water?

  Fizzing, dissolving, heating, and precipitate
• What happens to the reactivity of Group 2 metals with water down the group?

  Reactivity increases down the group
• What is the reaction of magnesium with warm water?

  Produces magnesium hydroxide and hydrogen
• How does the reaction of magnesium with warm water compare to steam?

  It is much slower and no flame
• What do Group 2 metals produce when reacting with acids?

  Salts and hydrogen
• How does the reactivity of Group 2 metals with acids change down the group?

  Increases down the group
• What is the reaction of calcium with hydrochloric acid?

  Ca + 2HCl → CaCl₂ + H₂
• What is the reaction of strontium with nitric acid?

  Sr + 2HNO₃ → Sr(NO₃)₂ + H₂
• What is the reaction of magnesium with sulfuric acid?

  Mg + H₂SO₄ → MgSO₄ + H₂
• What happens when barium reacts with sulfuric acid?

  Reacts slowly due to insoluble barium sulfate
• Why do other acids like hydrochloric or nitric not have the same effect as sulfuric acid on barium?

  They form soluble Group 2 salts
• What is calcium hydroxide used for in agriculture?

  To neutralise acidic soils
• What happens if too much calcium hydroxide is added to soil?

  Soil becomes too alkaline for crops
• How is magnesium hydroxide classified in terms of solubility?

  Partially soluble in water