Science Stage 8 Paper 1 Mark Scheme Notes

Science Stage 8 Paper 1 Mark Scheme From 2020

General Guidelines on Marking

• Descriptive answers can be expressed in a variety of ways; professional judgment should be used, matching marking points and information in the mark scheme.
• Phonetically correct answers are typically credited unless the word has a different scientific meaning.
  • Example: "antena" is accepted for "antennae," but "anthen" is not for "anther."
• Answers do not need to be grammatically correct.
• Significant figures will be indicated in the question or mark scheme.
• All marking points are independent unless specified.

Annotations and Abbreviations

• / OR: Alternate responses for the same marking point.
• ( ): Words or units in brackets do not need to be stated.
  • Example: (recycles or releases or provides) minerals = minerals scores the mark
• Underline: Exact word is required.
• Accept: An acceptable response.
• Do not accept: Indicates an incorrect response that would contradict another correct alternative.
• Ignore: Indicates an irrelevant answer that is not creditworthy; full marks can still be achieved with answers that are ignored.
• Note: Provides extra information when necessary.
• ecf: Error carried forward; marks are awarded if an incorrect response has been carried forward from earlier working, provided the subsequent working is correct.
• ora: Or reverse argument.
  • Example: "as mass increases, volume increases" can be written as "mass decreases, volume decreases."

Question 1(a)(i)

• X = rib(s) (cage)
• Y = diaphragm
• Each correct answer = 1 mark
• Ignore intercostal muscles

Question 1(a)(ii)

• rib(s) (cage) moves up / moves out
• diaphragm contracts /moves down / flattens
• Each correct answer = 1 mark

Question 1(b)(i)

• stop-watch /timer
• Accept data logger
• Ignore chest band / spirometer

Question 1(b)(ii)

• (running) speed

Question 1(b)(iii)

• (same) duration /(same) person doing the running /(same) breathing rate at start

Question 1(b)(iv)

• in a table/ graph / bar chart
• Do not accept pie chart

Question 2(a)

• positive charge on protons or nucleus and negative charge on electrons attract each other
• Each correct answer = 1 mark

Question 2(b)

• any two from:
  • different number of electrons /more electrons
  • different number of protons /more protons
  • different size (of electron cloud, nucleus or atom)/ larger size
• Assume answer refers to sodium unless lithium specified
• Accept different number of neutrons / more neutrons
• Accept higher level answers from Stage 9 e.g. Na has 3 shells

Question 3(a)(i)

• reflected ray drawn (with correct arrow) and angle of incidence approximately equal to angle of reflection by eye

Question 3(a)(ii)

• first refracted ray bends towards normal = 1 mark
• second refracted ray bends away from normal = 1 mark
• Ignore arrows on rays

Question 3(b)

• dispersion

Question 4(a)

• any one from
  • growth
  • repair
• Accept (makes) enzymes /(makes) muscles / (makes) hormones /(makes) skin /(makes) hair/ lactation
• Ignore for strength / energy

Question 4(b)

• water
• Ignore vitamins, salts or minerals

Question 4(c)(i)

• 194 (kJ)

Question 4(c)(ii)

• carbohydrate

Question 4(d)

• 4 g of protein RDA = 80 g
• correct answer = 2 marks
• sight of 4g of protein or $4 \times 20 = 1$ mark
• Accept ecf of $20 \times$ mass of protein

Question 5(a)

• idea that different dyes move across the paper at different speeds
• Accept different dyes have different attraction to the paper

Question 5(b)

• A the spots from ink A match the spots from the ink from the letter (exactly)
• if any other letter given = 0 marks for the question

Question 6(a)

• two lines going from N to S and not crossing e.g.

Question 6(b)

• increase the number of turns (of wire)
• increase the number of cells / increase the current
• each correct answer = 1 mark
• Accept have 7 or more turns (of wire)
• Accept have a larger voltage or potential difference

Question 7(a)

• any two from
  • yes (evidence shows that) iguanodons lived in lush vegetation which grew in warm conditions
  • yes (evidence shows that) mammoths had thick woolly covering showing adaptations to cold conditions
  • no because (idea of) one is in winter and one is in summer
  • no because no evidence for what happens in between
• yes or no only = 0 marks
• Accept maybe with one reason for yes and one reason for no

Question 7(b)

• any one from
  • yes because (evidence shows that) almost 120 million years between hot and cold conditions
  • yes because (evidence shows that) almost 120 million years between iguanodon and mammoth conditions
  • yes because Europe is now warmer than it was 4000 years ago when mammoths existed
  • no because you cannot tell how long either iguanodon or mammoth lived on Earth
  • no because there is no evidence for time between 4000 years and 120 million years ago
• yes or no only = 0 marks

Question 8(a)

• temperature increases
• Accept mixture gets hotter

Question 8(b)

• endothermic
• Accept answer written in table but answer line takes precedence

Question 8(c)

• metals
• non-metals
• inert
• explosive
• Accept any indication of the correct answer, e.g. underlining or ticking but circling takes precedence

Question 9(a)

• (speed =) 7.69 / 7.7 m / s or metres per second
• correct speed = 1 mark
• correct units = 1 mark
• Accept 7.692307 correctly rounded or truncated
• Do not accept 8
• Accept m s–1

Question 9(b)

• B and C
• if more than one box ticked = 0 marks
• Accept any indication of the correct answer, e.g. circling or underlining but ticking takes precedence

Question 10(a)

• (idea that the asteroids are) too small to be seen /too dim to be seen / too far away to be seen / cannot be seen without the aid of powerful telescope

Question 10(b)

• Galle
• Herschel
• Lippershey
• Piazzi

Question 10(c)(i)

• (pieces of) rock
• Accept metals, e.g. nickel and iron

Question 10(c)(ii)

• they are too small / not spherical

Question 10(d)

• any two from
  • can show more detail
  • can see even the smallest asteroids
  • can see more asteroids
  • can see the asteroids that are further away

Question 11(a)

• $H<em>2SO</em>4$
• Accept any order of symbols

Question 11(b)(i)

• idea of a model showing the similarity of like features for comparison

Question 11(b)(ii)

• high concentration – a lot of children in the room
• low concentration – a few children in the room
• each correct answer = 1 mark

Question 12

• prediction – diameter of balloon increases because at higher temperatures particles move faster or have more energy
• particles spread out /greater distance between particles / balloon walls pushed out
• each correct answer = 1 mark
• Accept particles hit surface of balloon harder
• Accept atoms or molecules instead of particles