Oxford Revise AQA GCSE Combined Science Foundation | Chapter C4 answers

C4: The Periodic Table

Question	Answers	Extra information	Mark	AO / Specification reference
01.1	protons neutrons		1 1	AO1 5.1.1.5
01.2	elements were missing elements were in the wrong place		1 1	AO1 5.1.2.2
01.3	left gaps for elements he predicted were still to be discovered swapped the order of some elements to group the elements by their chemical properties		1 1	AO1 5.1.2.2
01.4	atomic protons		1 1	AO2 5.1.2.2
02.1	Q		1	AO2 5.1.2.1
02.2	R because its outer electron shell/highest energy level is full/atoms have stable arrangements of electrons		1 1	AO2 5.1.2.4
02.3	P and S	both required for the mark	1	AO2 5.1.2.1
03.1	Group 0 – Noble Gases Group 1 – Alkali Metals Group 7 – Halogens	one mark for one correct two marks for all correct	2	AO1 5.1.2.4 5.1.2.5 5.1.2.6
03.2	2,8,8	one mark for eight electrons in outermost shell one mark for 2,8 in inner shells	2	AO2 5.1.2.4
03.3	stable arrangement of electrons/full outer shell of electrons		1	AO1 5.1.2.4
03.4	2,8,1		1	AO1 5.1.2.5
03.5	sodium oxide		1	AO1 5.1.2.5
03.6	more reactive		1	AO2 5.1.2.5
03.7	argon has a higher atomic mass than potassium, so potassium and argon would be swapped however, then potassium and argon would not share the properties of the other elements in their group/argon has a lower atomic number than potassium		1 1	AO2 5.1.2.1
04.1	seven		1	AO1 5.2.1.6
04.2	fluorine		1	AO1 5.1.2.6
04.3	hydrogen bromide – middle sodium chloride – top		1 1	AO2 5.1.2.6 5.2.1.2 5.2.1.4
04.4	displacement reaction no displacement reaction no displacement reaction		1 1 1	AO2 5.1.2.6
05.1	metals		1	AO1 5.1.2.5
05.2	lithium < sodium < potassium < rubidium < caesium	one mark for one correct, two mark for three correct, three marks for all correct	3	AO1 5.1.2.5
05.3	sodium + chlorine – sodium chloride sodium + water – sodium hydroxide + hydrogen sodium + oxide – sodium oxide		1 1 1	AO2 5.1.2.5
05.4	to stop them reacting with the oxygen or water in the air		1	AO3 5.1.2.5
05.5	dull grey appearance is sodium oxide because sodium has reacted with oxygen (in the air)/tarnishes metal is soft and easy to cut as it is a pure metal the inside is shiny are it is pure metal and has not had the chance to react with oxygen		1 1 1 1 1	AO2 5.1.2.5
05.6	Level 3: Observations are detailed and accurate. The writing is clear, coherent and logical and comparisons are clearly made.		5-6	AO3 5.1.2.5
	Level 2: Observations generally correct, although may lack detail. The writing is mainly clear, although the structure may lack logic and comparisons are not always clear		3-4
	Level 1: Some correct observations. The writing lacks clarity, coherence and logic, and the comparisons are not clearly expressed.		1-2
	No relevant content.		0
	Indicative content universal indicator would change colour to purple as solution becomes more alkali because potassium hydroxide is produced metal would ‘fizz’ or whizz around as the hydrogen gas was released flames would be seen exothermic reaction/give off energy potassium would ‘disappear’ as it reacted to form potassium hydroxide
06.1	non-metal right of the periodic table		1 1	AO1 5.1.2.3
06.2	eight		1	AO1 5.1.2.4
06.3	helium < neon < argon < radon	one mark for two correct	2	AO1 5.1.2.4
07.1	metal		1	AO1 5.1.2.3
07.2	rubidium hydroxide and hydrogen		1	AO2 5.1.2.5
07.3	rubidium + oxygen → rubidium oxide		1	AO1 5.1.2.5
07.4	2Na(s) + Br₂(l) → 2NaBr(s)	one mark for balancing one mark for state symbols	2	AO2 5.1.2.5
07.5	rubidium is more reactive than sodium because it is further down Group 1 outer electron is further from the nucleus so easier to transfer to chlorine/easier to remove		1 1 1 1	AO1 5.1.2.5
08.1	+2		1	AO2
08.2	magnesium ion has the electron arrangement: 2,8 (drawn as dots/crosses) magnesium should be in square brackets with a 2+ positive charge there should be 2 chlorine ions, with the electron arrangement 2,8,7 (drawn as crosses/dots) each should have one additional electron from magnesium (drawn as a dot/cross) chlorine should be in square brackets with a 1– charge, and a subscript 2 to represent Cl₂	one mark for magnesium one mark for chlorine one mark for charges and two chlorine atoms	3	AO2
08.3	strontium will be more reactive than magnesium in strontium, the outer shell is further from the nucleus than in magnesium so easier to remove the 2 outer electrons		1 1 1	AO3 5.1.2.5
08.4	sodium will be more reactive only needs to lose one electron, compared to magnesium which needs to lose two		1 1	AO3 5.1.2.5
09.1	potassium ion has the electron arrangement: 2,8,8 (drawn as dots/crosses) potassium should be in square brackets with a 1+ positive charge bromine ion has the electron arrangement 2,8,8,7 (drawn as crosses/dots) with an additional electron from potassium (drawn as a dot/cross) bromine should be in square brackets with a 1– charge	one mark for potassium one mark for bromine one mark for charges	3	AO2 5.1.2.5 5.1.2.6
09.2	B potassium chloride bromine		1 1	AO2 5.1.2.6
09.3	Group 1 reactivity increases as you go down the group atoms have to lose 1 electron to achieve stable electron arrange/eight electrons in the outer shell outer electron is further from nucleus, so easier to remove Group 7 reactivity decreases as you go down the group atoms have to gain one electron to achieve stable electron arrange/eight electrons in the outer shell outer shell further from the nucleus, so harder to attract/further from positive charge of the nucleus		1 1 1 1 1 1	AO1 5.1.2.5 5.1.2.6
09.4	sodium + water → sodium hydroxide + hydrogen	one mark for reactants, one mark for products	2	AO2 5.1.2.5
10.1	Group 0 – inert Group 1 – react with water to make alkaline solutions Group 7 – react with metals to make ionic compounds		1 1 1	AO1 5.1.2.4 5.1.2.5 5.1.2.6
10.2	Group 1 gets more reactive down the group Group 1 loses outer electron to form full outer shell/nearest Noble Gas electron is further from the nucleus, so becomes easier to remove Group 7 gets less reactive down the group Group7 atoms gain electron to form full outer shell/nearest Noble Gas less attraction felt by positive nucleus charge further away from nucleus		1 1 1 1 1 1	AO2 5.1.2.5 5.1.2.6
10.3	inert atoms already have full outer electron shell		1 1	AO1 5.1.2.4
11.1	Alkali Metals		1	AO1 5.1.2.6
11.2	they have the number of electrons in the shell furthest from the nucleus		1	AO1 5.1.2.1
11.3	caesium bromide		1	AO2 5.1.2.5 5.1.2.6
12.1	iron		1	AO1 5.1.2.3
12.2	harder distorted slide over		1 1 1	AO1 5.2.2.7
12.3	strong metallic bonds lots of energy needed to overcome them		1 1	AO2 5.2.2.7

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