did not appear because they had not been discovered or they are unreactive or they did not form compounds

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2 Mark schemes did not appear because they had not been discovered they are unreactive they did not fm compounds arranged in der of atomic / proton number elements in the same group have the same number of electrons in the outer shell chline>bromine>iodine table shows that chline displaces bromine and iodine and bromine displaces iodine (d) Cl 2 (aq) + 2 Br (aq) Br 2 (aq) + 2 Cl (aq) crect fmulae crect balancing crect state symbol (e) the further down the group, the halogen becomes less reactive because outer electrons are further from the nucleus so less attractive fce on an incoming electron [0] 2 Y W V (d) W (e) X [5] Page 2 of 0

3 3 (iron) is a metal accept transition element allow (iron) had different properties (to oxygen and sulfur) igne electrons so that elements with similar properties could be placed together allow to make the pattern fit igne undiscovered elements atomic number(s) allow proton number(s) (d) all have one electron in the outer shell (highest energy level) allow same number of electrons in the outer shell (highest energy level) (so they) have similar properties react in the same way allow specific reactions e.g. with water [5] 4 (i) Na allow sodium Cu allow copper (iii) C allow carbon (iv) He allow helium H allow hydrogen do not allow H 2 [5] 5 if placed consecutively, then elements would be in wrong group / have wrong properties allow some elements didn t fit pattern Page 3 of 0

4 left gaps (elements placed in) atomic / proton number der (elements in ) same group have same number of outer electrons any one from: number of protons = number of electrons reactions/(chemical) properties depend on the (outer) electrons number of shells gives the period allow number of shells increases down the group (i) (transition elements usually) have same / similar number of outer / 4th shell electrons allow 2 electrons in outer shell (because) inner (3rd ) shell / energy level is being filled igne shells overlap 2 nd shell / energy level can (only) have maximum of 8 electrons accept no d-bitals 2 nd shell / energy level cannot have 8 electrons [8] 6 sodium has a lower density sodium is me reactive hydrogen OH (aq) [4] Page 4 of 0

5 Br 2 allow multiples / fractions if crectly completed and balanced 7 (i) a crect link between any two named elements eg same group / column same properties / number of outer electrons allow some link between any two elements in the same group (in both Newlands and the modern periodic table) any two from: igne statements about lack of evidence / proof elements still being discovered no gaps f undiscovered elements some boxes have 2 elements in them metals and non-metals in same column / mixed up accept some elements in same column have different properties. allow any sensible suggestion about misplaced elements eg copper in group elements pattern f first 6 so elements only allow did not wk f all elements 2 (i) Cl > Br > I accept reactivity / it decreases down the group I < Br < Cl Cl has 2 reactions, Br has reaction, I doesn t react owtte allow Cl has most / me reactions and I has least / less reactions (must be clear about where Br fits in) (iii) (they) have 7 outer electrons allow (they) have 7 electrons in highest occupied (energy) level / shells / rings Page 5 of 0

6 outer / last / final must be mentioned once in crect context, otherwise max 2 marks comparative required on all three points accept converse ie less reactive up group down group (atom / elements) bigger outer electrons (level / shell /ring) further from nucleus / centre igne me electrons me shells / level / rings do not accept me outer shells f this mark fce(s) / attraction(s) are weaker allow electron(s) attracted less easily allow electron(s) less under influence (of nucleus) me shielding attracts less do not accept magnetic / gravitational / intermolecular fces electron(s) lost me easily allow electron(s) me likely to be lost allow easier to give away [0] 8 (i) (iii) gains an electron me easily than Cl because the higher the energy level the less easily an electron is gained each f mark 4 Page 6 of 0

7 (i) very unreactive give reactivity trend (iii) fluine reacted with silicon from glass each f mark Reactivity increases down the group radon likely to react because lower in group than xenon me reactive than xenon Kr may may not react higher in group than xenon less reactive than xenon any 5 f mark each 2 5 [4] 9 (i) same number of electrons allow all have 7 electrons in outermost shell fluine has fewer shells than iodine / less shielding gains electrons me easily / me pull outermost shell full no tendency to lose / gain electrons [6] 0 (i) undiscovered elements owtte they would be in the wrong group / have the wrong / different properties / don t fit the pattern owtte allow atomic weights may have been wrong Page 7 of 0

8 (i) any three from: elements arranged in proton / atomic number der igne mass number / atomic weight / neutrons throughout group: elements in the same group / column have same number of outer electrons owtte group: number of shells increase down group period: elements in the same period / row have the same number of shells / energy levels period: number of protons / electrons increase across period atomic number: link of atomic number to number of protons atomic number gives number of electrons 3 it would mean splitting a proton / electron implication of splitting proton / electron must be a comparison (outer) electron closer (to nucleus) accept fewer (electron) shells / energy levels fluine is the smaller/est stronger/est attraction (to nucleus) owtte do not allow magnetic / intermolecular fces less screening (by inner electrons) electron gained me easily need some indication of outer electron shell somewhere in explanation otherwise max of 2 marks [9] all have seven electrons in their outer shell / energy level Page 8 of 0

9 must be comparative in all points converse chline atom is smaller than bromine atom chline atom has fewer shells than bromine atom outer shell / energy level of chline has stronger (electrostatic) attraction to the nucleus than bromine outer shell of chline is less shielded from the nucleus than bromine so chline me readily gains an extra electron [4] 2 (i) hydrogen accept H 2 allow H hydroxide accept OH allow OH do not accept lithium hydroxide Page 9 of 0

10 any two from: it = potassium potassium: accept converse f lithium reacts / dissolves faster allow reacts me vigously / quickly / violently / explodes igne reacts me bubbles / fizzes faster allow fizzes me allow me gas moves faster (on the surface) allow moves me melts allow fms a sphere produces (lilac / purple) flame allow catches fire / ignites do not accept other colours 2 [4] Page 0 of 0