Periodicity (AQA A Level Chemistry)

Exam Questions

3 hours45 questions
11 mark

Sodium sulfide, Na2S, is a reactive yellow solid, produced when sodium and sulfur react together.

How does the ionic radius of sodium compare with that of sulfur?

  • The ions have the same ionic radii

  • The atoms have the same atomic radii

  • Sodium < sulfur

  • Sodium > sulfur

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21 mark

The trends in three physical properties of the elements of Period 3 are shown in the graphs below.

UX5_lMDK_16

V-nM-xW0_17

18

Which physical property is not illustrated?

  • first ionisation energy

  • atomic radius

  • melting point

  • electrical conductivity

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31 mark

What is the correct classification for the element zirconium, Zr?

  • s block

  • d block

  • f block

  • p block

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41 mark

Which Period 3 element has the highest melting point?

  • Sulfur

  • Argon

  • Silicon

  • Aluminium

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51 mark

What is the correct equation for the second ionisation energy of rubidium, Rb?

  • Rb+ (g) → Rb2+ (g) + e-

  • Rb (g) → Rb+ (g) + e-

  • Rb2+ (g) → Rb3+ (g) + e-

  • Rb2+ (g) + e- → Rb+ (g)

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61 mark

Which statement is not correct for Group 2 metals?

  • An unpaired electron is present in the s orbital

  • Chemical reactivity increases with increasing atomic number

  • The first ionisation energy decreases with increasing atomic number

  • Atomic radius increases with increasing atomic number

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71 mark

Which Period 2 element from sodium to silicon, has the largest atomic radius?

  • magnesium

  • sodium

  • silicon

  • aluminium

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81 mark

The trend in melting points of some Period 3 elements can be represented as:

S8 > P4 > Cl2

What intermolecular force explains this trend in melting points?

  • permanent dipole-dipole

  • covalent bonding

  • hydrogen bonding

  • van der Waals

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91 mark

Why does aluminium have a higher melting point than magnesium?

  • aluminium has its valence electron in the p orbital

  • lower charge on the cation and increasing number of delocalised electrons

  • higher charge on the cation and increasing number of delocalised electrons

  • higher charge on the cation and increasing number of localised electrons

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101 mark

Why is the second ionisation energy of magnesium higher than the first ionisation energy?

  • less shielding

  • ionic radius increases

  • nuclear charge is increasing

  • greater attraction between positive nucleus and outer electron

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11 mark

What is the correct order of the decreasing melting points of these period 3 chlorides shown?

 

highest melting point     rightwards arrow     lowest melting point

A

SiCl4

PCl3

NaCl

MgCl2

B

MgCl2

NaCl

SiCl4

PCl3

C

NaCl

MgCl2

PCl3

SiCl4

D

NaCl

MgCl2

SiCl4

PCl3

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    21 mark

    Consecutive elements X, Y and Z, are in the third period of the periodic table. Element Y has the highest first ionisation energy and the lowest melting point of these three elements.

    What could be the identities of X, Y and Z?

    • silicon, phosphorus, sulfur

    • sodium, magnesium, aluminium

    • aluminium, silicon, phosphorus

    • magnesium, aluminium, silicon

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    31 mark

    Which graph correctly shows the relative melting points of period 3 elements plotted against their relative electronegativities?

    • FsovnU2-_19

    • Xwi40r6c_20

    • _7rqM5eI_21

    • rFwEzgq-_22

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    41 mark

    Period 3 elements Q and R react together to form compound S.

    Element Q has the second smallest atomic radius in period 3.

    Apart from argon, there is only one element in period 3 which has a lower melting point than element R.

    Which compound could be S?

    • Li2S

    • CaS

    • PCl3

    • MgCl2

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    51 mark

    Period 3 elements can react with chlorine to produce the following chlorides:

    MgCl2       AlCl3      SiCl4      PCl3      SCl2

    Period 3 elements also react with oxygen to produce oxides.

    Which of the elements have a higher oxidation state in their oxides than in the above chlorides?

    • P and S

    • Mg, P and S

    • Mg and P

    • Mg, Al, Si, P and S

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    61 mark

    The second ionisation energy of calcium is 1145 kJ mol-1.

    Which equation correctly represents this statement?

    • Ca+(g) → Ca2+(g) + e-          ΔH = -1145 kJ mol-1

    • Ca(g) → Ca2+(g) + 2e-          ΔH = +1145 kJ mol-1

    • Ca+(g) → Ca2+(g) + e-         ΔH  = +1145 kJ mol-1

    • Ca(g) → Ca+(g) + e-            ΔH = -1145 kJ mol-1

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    71 mark

    The first six ionisation energies of an element in period 3 are shown below.

     

    1st

    2nd

    3rd

    4th

    5th

    6th

    Ionisation energy kJ mol-1

    787

    1577

    3232

    4356

    16 091

    19 805

    What is the identity of the period 3 element?

    • Chlorine

    • Phosphorus

    • Carbon

    • Silicon

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    81 mark

    An element in the d block of the periodic table forms a +4 ion and has the electron configuration of [Ar] 3d1.

    What is the identity of the element?

    • Chromium

    • Copper

    • Vanadium

    • Silicon

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    91 mark

    Electron configurations for atoms of different elements are shown below.

    Which electron configuration represents the element with the largest first ionisation energy?

    • 1s22s22p63s2

    • 1s22s22p63s23p4

    • 1s22s22p63s23p6

    • 1s22s22p63s23p64s2

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    101 mark

    How are the elements ordered in the periodic table?

    • By atomic number

    • According to relative atomic mass 

    • By reactivity

    • In order of electronegativity

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    11 mark

    Which of these elements has the third lowest first ionisation energy in its period and the third smallest atomic radius in its group?

    • Magnesium

    • Gallium

    • Potassium

    • Calcium

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    21 mark

    The graph shows the first ionisation energies of four consecutive elements. 

    One of the elements reacts with hydrogen to form a covalent compound with formula HX. 

    Which element could be X?

    UHSpCDqM_24

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      31 mark

      The successive ionisation energies for element R are shown.

       

      1st

      2nd

      3rd

      4th

      5th

      6th

      Ionisation energy / kJ mol-1

      950

      1800

      2700

      4800

      6000

      12 300

      What is the oxidation state of element R when bonded to chlorine?

      • +1

      • +2

      • +3

      • +4

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      41 mark

      Element Q reacts with sulfur. The first five successive ionisation energies for element Q are shown.

       

      1st

      2nd

      3rd

      4th

      5th

      Ionisation energy value / kJ mol−1

      738

      1450

      7733

      10543

      13630

      What is the formula of the compound when element Q reacts with sulfur?

      • QS

      • QS3

      • Q3S

      • Q2S

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      51 mark

      The species Cl -, K+ and Ar are isoelectronic. This means that they have the same number of electrons.

      In which order do their radii decrease?

       

      largest     rightwards arrow     smallest

      A

      K+

      Cl -

      Ar

      B

      Cl -

      Ar

      K+

      C

      K+

      Ar

      Cl -

      D

      Ar

      K+

      Cl -

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        61 mark

        Which statement about energy levels and electrons is correct?

        • 18 is the maximum number of electrons in the 4th energy level

        • 10 is the maximum number of electrons in one d orbital

        • Yttrium is the first element with an electron in an f subshell

        • In a main energy level, the subshell with the highest energy is f

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        71 mark

        How many electrons are removed from 2.02 × 10−2 g of Ne (g) atoms to form Ne+ (g) ions?

        • 2.46 x 1023

        • 1.22 × 1022

        • 6.02 × 1020

        • 1.22 × 1021

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        81 mark

        Which of the following pairs does the second element have a higher 1st ionisation energy than the first element?

         

        First element

        Second element

        A

        Mg

        Al

        B

        N

        O

        C

        Ne

        Na

        D

        K

        Na

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          91 mark

          Element J has a lower first ionisation energy and higher melting point than the element preceding it in the periodic table. 

          Its ion is isoelectronic with argon. 

          What is the identity of element J?

          • Na

          • S

          • P

          • Al

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          101 mark

          The successive ionisation energies for element X are shown.

          Ionisation 

          Ionisation energy / kJ mol-1

          1st

          578

          2nd

          1817

          3rd

          2745

          4th

          11 577

          5th

          14 842

          6th

          18 379

          What is the electron configuration for element X?

          • [Ne] 3s1

          • [Ne] 3s13p2

          • [Ne] 3s23p1

          • [Ne] 3s23p2

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