All 80 decoded questions of ESAT 2017, in paper order. · A question can reward more than one move, so the counts overlap.
ENGAA 2017 Section 1, Part B (Mathematics questions) 18 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
55 Oxygen debt is the extra oxygen above rest taken in during recovery Key method Biology Animal Physiology: Systems, Homeostasis & Disease 1 other sitting Same method, other sittings
56 Most mutations are neutral, of the rest most are harmful and beneficial ones are rare Pavlov Biology Inheritance, Variation & Evolution only this sitting Same method, other sittings
This one has only struck here so far.
57 Ecological abundance: frequency is presence in quadrats, density is count per area, and both need a random sample Key method Biology Ecology & Plant Physiology 5 other sittings Same method, other sittings
58 Mitosis keeps the chromosome number and makes two cells, meiosis halves it and makes four Every body cell shares one genome, and the male gamete fixes the sex Read a stem cell division by counting what the two daughters are Key method Biology Membrane Transport, Cell Division & Reproduction 6 other sittings Same method, other sittings
59 Weigh the modal word: always or must needs certainty, could or may needs only one plausible mechanism Key method Biology Ecology & Plant Physiology 3 other sittings Same method, other sittings
60 Prokaryote versus eukaryote: the defining feature contrast (wall, nucleus, mitochondria, chloroplasts) Animal cells never have a cell wall or chloroplasts: use it as an instant eliminator Pavlov Biology Cells 6 other sittings Same method, other sittings
61 Energy through trophic levels: about ten per cent passes on, step by step, and efficiency is out over in Tunnel Biology Ecology & Plant Physiology 1 other sitting Same method, other sittings
62 Bacterial binary fission is not mitosis, and the population doubles each division Pavlov Biology Membrane Transport, Cell Division & Reproduction 1 other sitting Same method, other sittings
63 Trace the auxin: shoots bend to light, roots to gravity, driven by uneven hormone from an intact tip Pavlov Biology Ecology & Plant Physiology 2 other sittings Same method, other sittings
64 Monohybrid cross Aa x Aa gives a 1:2:1 genotype ratio and a 3:1 phenotype ratio Probability of a specific sex and a specific genotype: multiply the two independent chances Tunnel Biology Inheritance, Variation & Evolution 5 other sittings Same method, other sittings
65 Osmosis moves water toward the more concentrated solution Pavlov Biology Membrane Transport, Cell Division & Reproduction 6 other sittings Same method, other sittings
66 Mitosis keeps the chromosome number and makes two cells, meiosis halves it and makes four Key method Biology Membrane Transport, Cell Division & Reproduction 6 other sittings Same method, other sittings
67 Read what actually measures a rate: quantity against time, and equal steps give rate proportional to one over time Key method Biology Ecology & Plant Physiology 2 other sittings Same method, other sittings
68 Could versus must: separate what the data proves from what it only allows Key method Biology Enzymes 2 other sittings Same method, other sittings
69 Trace the auxin: shoots bend to light, roots to gravity, driven by uneven hormone from an intact tip Pavlov Biology Ecology & Plant Physiology 2 other sittings Same method, other sittings
70 Could, may or might means find one valid scenario, not prove it always holds Read a coding strand in non-overlapping triplets from the left and translate with the table The genetic code is degenerate: a base change need not change the amino acid or the phenotype Substitution hits one codon; an insertion or deletion reframes everything downstream Key method Biology DNA, Protein Synthesis & Gene Technology 4 other sittings Same method, other sittings
71 Oxygen sag below organic pollution: bacteria strip the oxygen, and indicator species track the curve Key method Biology Ecology & Plant Physiology 3 other sittings Same method, other sittings
72 A lethal or non-surviving genotype: delete it and re-read the ratio among survivors Key method Biology Inheritance, Variation & Evolution 2 other sittings Same method, other sittings
NSAA 2017 Section 1 Part B (ESAT Physics) 17 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
37 Read a nuclide symbol into protons, neutrons and electrons Isoelectronic species share an electron count but differ in protons Pavlov Chemistry Atomic Structure, Bonding & the Periodic Table 5 other sittings Same method, other sittings
38 Judge a reaction as redox from its type before assigning oxidation numbers Electron direction in a half-equation: left means reduction, right means oxidation Key method Chemistry Chemical Reactions, Acids, Bases & Redox 5 other sittings Same method, other sittings
39 Strong versus weak acid: only the hydrogen ion properties differ, not the amount of acid Key method Chemistry Chemical Reactions, Acids, Bases & Redox 2 other sittings Same method, other sittings
40 Screen an equilibrium with the three Le Chatelier levers Key method Chemistry Rates of Reaction & Energetics 2 other sittings Same method, other sittings
41 Rf equals spot distance over solvent-front distance Interpreting a chromatogram: purity, identity, mobility and phases Pavlov Chemistry Organic Chemistry, Separation & Analysis 6 other sittings Same method, other sittings
42 Electron configuration gives the Period, the Group and the element Oxide formula and acid-base character straight from the group Pavlov Chemistry Atomic Structure, Bonding & the Periodic Table 3 other sittings Same method, other sittings
43 An ionic formula must be charge neutral: cross the ion charges Ionic equations keep only the ions that change; spectators do not affect mass or rate Pavlov Chemistry Chemical Reactions, Acids, Bases & Redox 2 other sittings Same method, other sittings
44 Recall Group 1 and Group 17 trends whole, without deriving them Pavlov Chemistry Atomic Structure, Bonding & the Periodic Table 3 other sittings Same method, other sittings
45 Aqueous electrolysis discharge rules: below hydrogen deposits, halide gives the halogen Cathode is reduction, anode is oxidation, and electrons flow from plus to minus outside Key method Chemistry Electrolysis & Metals 5 other sittings Same method, other sittings
46 Empirical formula: masses to moles to the simplest whole number ratio Tunnel Chemistry Quantitative Chemistry 3 other sittings Same method, other sittings
47 Read the balanced equation directly in gas volumes, and track the change in the number of gas molecules Key method Chemistry Quantitative Chemistry 3 other sittings Same method, other sittings
48 Read a rate-time curve as two separate things: plateau and steepness Key method Chemistry Rates of Reaction & Energetics 4 other sittings Same method, other sittings
49 Bond-energy balance: broken minus formed, counting every bond Tunnel Chemistry Rates of Reaction & Energetics 4 other sittings Same method, other sittings
50 Electron accounting: turn charge into moles, then read every amount off the half-equations Cathode is reduction, anode is oxidation, and electrons flow from plus to minus outside Molten electrolysis always splits the compound into its two elements Tunnel Chemistry Electrolysis & Metals 5 other sittings Same method, other sittings
51 Limiting reagent by moles over coefficient, and the graph plateau marks the exact stoichiometric point Tunnel Chemistry Quantitative Chemistry 2 other sittings Same method, other sittings
52 Relative atomic mass as an abundance-weighted mean, forwards or reversed Bound the relative atomic mass between the isotope masses to eliminate options Tunnel Chemistry Atomic Structure, Bonding & the Periodic Table 6 other sittings Same method, other sittings
53 Read a rate-time curve as two separate things: plateau and steepness Key method Chemistry Rates of Reaction & Energetics 4 other sittings Same method, other sittings
NSAA 2017 Section 1, Part A (Mathematics questions) 15 decoded The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
1 Factor out surds before expanding or rationalising Exploit algebraic identities to skip expanding surds Key method Pure Number & Units 3 other sittings Same method, other sittings
2 Polynomial Inequalities Tunnel Pure Algebra, Functions & Graphs 2 other sittings Same method, other sittings
3 Unwrapping Squared Formulas Pavlov Pure Algebra, Functions & Graphs 1 other sitting Same method, other sittings
4 Simultaneous Linear Equations by Elimination Tunnel Pure Algebra, Functions & Graphs 2 other sittings Same method, other sittings
5 Setting up the proportionality constant Tunnel Pure Ratio & Proportion 5 other sittings Same method, other sittings
6 Polynomial Inequalities Tunnel Pure Sequences & Series 2 other sittings Same method, other sittings
7 Algebraic Fraction Simplification Pavlov Pure Algebra, Functions & Graphs 6 other sittings Same method, other sittings
8 Parallelogram missing vertex: equate opposite vectors Pavlov Pure Coordinate Geometry only this sitting Same method, other sittings
This one has only struck here so far.
9 Reduce exponential equations to a single prime base Pavlov Pure Number & Units 3 other sittings Same method, other sittings
10 Fill the two-way table for overlapping categories Tunnel Prob & Stats Probability & Statistics 2 other sittings Same method, other sittings
11 Regular polygons: work with exterior angles, not interior Pavlov Pure Geometry 3 other sittings Same method, other sittings
12 Bearings: use back-bearings and subtraction to find angles Pavlov Pure Geometry 3 other sittings Same method, other sittings
14 Scaling laws for similar figures and solids Pavlov Pure Ratio & Proportion 4 other sittings Same method, other sittings
15 Set up algebraic probability trees Tunnel Prob & Stats Probability & Statistics 4 other sittings Same method, other sittings
16 Overlay a coordinate system for complex intersecting shapes Key method Pure Geometry 5 other sittings Same method, other sittings
NSAA 2017 Section 1, Part C (Chemistry questions) 4 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
35 Sector and Segment Mechanics Tunnel Pure Trigonometry 2 other sittings Same method, other sittings
37 Common-Base Conversion Key method Pure Exponentials & Logarithms 1 other sitting Same method, other sittings
41 Geometry Optimisation via Quadratics Tunnel Pure Trigonometry 1 other sitting Same method, other sittings
51 Sequential Curve Transformations Tunnel Pure Algebra, Functions & Graphs 1 other sitting Same method, other sittings
NSAA 2017 Section 1, Part D (Biology questions) 8 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
73 Rationalise the denominator using the conjugate Tunnel Pure Number & Units 2 other sittings Same method, other sittings
75 Intersection of Solution Sets Pavlov Pure Trigonometry only this sitting Same method, other sittings
This one has only struck here so far.
77 Substitute to a Polynomial (Exponentials & Logs) Work Backwards from Logarithmic Options Tunnel Pure Exponentials & Logarithms 3 other sittings Same method, other sittings
79 Coefficient Matching from Turning Points Key method Pure Differentiation 1 other sitting Same method, other sittings
81 Look Ahead in Binomial Expansions Key method Pure Sequences & Series 2 other sittings Same method, other sittings
85 Factor and Remainder Theorem Pavlov Pure Sequences & Series 3 other sittings Same method, other sittings
87 Factor and Remainder Theorem Polynomial Inequalities Pavlov Pure Algebra, Functions & Graphs 4 other sittings Same method, other sittings
89 Perpendicular lines: the product of their gradients is -1 Pavlov Pure Coordinate Geometry 2 other sittings Same method, other sittings
NSAA 2017 Section 1, Part E (Mathematics questions) 18 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
19 Read a motion graph by gradient and area, one phase at a time Answer only the phase the question names: every other phase area is an offered option Tunnel Physics Kinematics & Forces 4 other sittings Same method, other sittings
20 Sort the three transfer modes by what each one actually requires Pavlov Physics Thermal Physics 2 other sittings Same method, other sittings
21 Classify a wave on the spectrum by converting band edges with the wave equation Tunnel Physics Waves, Sound & the Electromagnetic Spectrum 3 other sittings Same method, other sittings
22 Find the current first: it is the hub of every electrical chain Pavlov Physics Electricity & Magnetism 4 other sittings Same method, other sittings
23 Energy lost, wasted or done against drag is the input total minus the useful total Key method Physics Energy, Work & Momentum 3 other sittings Same method, other sittings
24 Turn measured times into distances with the right geometric factor for reflected or multi-speed signals Key method Physics Waves, Sound & the Electromagnetic Spectrum 3 other sittings Same method, other sittings
25 Nuclear reactions: balance nucleon number and proton number across the arrow Tunnel Physics Radioactivity 2 other sittings Same method, other sittings
26 Power is energy per second: convert the time first, and use force times velocity at constant speed Efficiency chain: multiply going out, divide coming back, never add the losses Pavlov Physics Energy, Work & Momentum 2 other sittings Same method, other sittings
27 Alpha and beta decay bookkeeping: fix the alpha count from the mass number first Tunnel Physics Radioactivity 5 other sittings Same method, other sittings
28 When only a ratio is asked, form the ratio and let the unknowns cancel Decide the direction of the change first, then read the spread of the options Key method Physics Matter 4 other sittings Same method, other sittings
29 Read the period and wavelength off wave graphs as half-cycle steps and reduce fractional periods Key method Physics Waves, Sound & the Electromagnetic Spectrum 2 other sittings Same method, other sittings
30 Find the current first: it is the hub of every electrical chain Read the option spread before computing: the distractors name the slip Pavlov Physics Electricity & Magnetism 6 other sittings Same method, other sittings
31 In a collision momentum carries signs and kinetic energy does not Key method Physics Energy, Work & Momentum 2 other sittings Same method, other sittings
32 Let the option list choose your units, and kill options by dimensions Key method Physics Matter 3 other sittings Same method, other sittings
33 Power is energy per second: convert the time first, and use force times velocity at constant speed Compound option tables: settle the cheapest quantity first and strike out Pavlov Physics Energy, Work & Momentum 3 other sittings Same method, other sittings
34 Half-life arithmetic: work in powers of one-half, never in logarithms Decay conserves atoms one for one: daughter equals initial daughter plus parent decayed Pavlov Physics Radioactivity 6 other sittings Same method, other sittings
35 Two scenarios compared: take the ratio, never recompute either one Key method Physics Energy, Work & Momentum 1 other sitting Same method, other sittings
36 Label the circuit with the two invariants, then carry the one given number across Choose the power formula by the shared quantity, then split power as R or as one over R Tunnel Physics Electricity & Magnetism 5 other sittings Same method, other sittings
