Periodic Table blocks and periodic trendsEdexcel International A Level Chemistry: Subtopic test

1. 1
   A student is sorting elements of the first four periods into the s, p and d blocks of the Periodic Table.

   (a)

   Which element is in the d block?

   [1 mark]

   • APotassium
   • BIron
   • CGallium
   • DKrypton

   (b)

   What is the maximum number of electrons in the third quantum shell (n = 3)?

   [1 mark]

   • A8
   • B10
   • C32
   • D18

   (c)

   Explain what is meant by the term periodic property and give one example.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   Melting and boiling temperatures vary across Period 2. Lithium melts at 181 °C and beryllium at 1287 °C. Carbon, as diamond, sublimes above 3500 °C. Nitrogen boils at −196 °C, oxygen at −183 °C, fluorine at −188 °C and neon at −246 °C.

   (a)

   Which Period 2 element is expected to have the highest melting temperature?

   [1 mark]

   • ACarbon (as diamond)
   • BLithium
   • CNitrogen
   • DNeon

   (b)

   Why does fluorine boil at a higher temperature than neon?

   [1 mark]

   • AThe strong covalent bond in F₂ is broken when fluorine boils
   • BNeon is held in a giant lattice with delocalised electrons
   • CF₂ molecules have more electrons than Ne atoms, so the London forces between them are stronger
   • DNeon atoms are heavier than fluorine molecules

   (c)

   Explain why the melting temperature of beryllium is much higher than that of lithium.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A student plots log₁₀ of the successive ionisation energies of magnesium against the number of electrons removed. The successive ionisation energies of magnesium are, in kJ mol⁻¹: 738, 1451, 7733, 10 543, 13 630, 17 995, 21 703, 25 656, 31 642, 35 462, 169 988 and 189 368.

   (a)

   Calculate log₁₀ of the first three ionisation energies of magnesium, to two decimal places, and state one reason why logarithms are used.

   [3 marks]

   (b)

   Describe where the large jumps occur in the graph and explain what they show about the electronic structure of magnesium.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   The melting temperatures of the Period 3 elements are, in °C: Na 98, Mg 650, Al 660, Si 1410, P₄ 44, S₈ 113, Cl₂ −101 and Ar −189. The first ionisation energies of the Group 2 elements are, in kJ mol⁻¹: Be 900, Mg 738, Ca 590, Sr 550 and Ba 503.

   (a)

   Explain the trend in melting temperature from sodium to argon, in terms of structure and bonding.

   [6 marks]

   (b)

   Explain the trend in first ionisation energy down Group 2, and predict, with a reason, how the first ionisation energy of radium (below barium) compares with that of barium.

   [6 marks]

   Total for question 4: 12 marks

End of questions