All 87 decoded questions of ESAT 2023, in paper order. · A question can reward more than one move, so the counts overlap.
ENGAA 2023 Section 1, Part B (Mathematics questions) 19 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 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
61 Classify the interaction: same species or different, and who benefits Pavlov Biology Ecology & Plant Physiology 1 other sitting Same method, other sittings
62 Plateaux and the compensation point: a level rate means another factor limits, a falling rate means denaturation Key method Biology Ecology & Plant Physiology 3 other sittings Same method, other sittings
63 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
64 Denaturation is loss of the active-site shape, caused by heat, extreme pH or boiling Biology arithmetic reflexes: percentage over the original, rate as amount over time, area as radius squared Structure implies function, and every enzyme is specific to its substrate Key method Biology Enzymes 5 other sittings Same method, other sittings
65 Volume in a capillary tube is a cylinder: pi times radius squared times length, radius is half the diameter Transpiration essentials: guard cells open when turgid, and a potometer measures water uptake not translocation Tunnel Biology Ecology & Plant Physiology 3 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 Prokaryote versus eukaryote: the defining feature contrast (wall, nucleus, mitochondria, chloroplasts) Magnification equals image size over actual size: fix the units first, then let the order of magnitude choose Pavlov Biology Cells 5 other sittings Same method, other sittings
68 Monohybrid cross Aa x Aa gives a 1:2:1 genotype ratio and a 3:1 phenotype ratio A recessive phenotype fixes the genotype, a dominant phenotype needs a test cross Tunnel Biology Inheritance, Variation & Evolution 5 other sittings Same method, other sittings
69 On numbered-statement items, bin the clause that reverses cause, sign or proportionality Key method Biology Animal Physiology: Systems, Homeostasis & Disease 2 other sittings Same method, other sittings
70 Menstrual cycle hormones, and menstruation is triggered by the fall in progesterone Pavlov Biology Animal Physiology: Systems, Homeostasis & Disease only this sitting Same method, other sittings
This one has only struck here so far.
71 Follow the product to fix the pH direction and read the indicator Key method Biology Enzymes 2 other sittings Same method, other sittings
72 Respiration in a data question: both respiration types release carbon dioxide, and a mass needs the volume not the concentration Key method Biology Cells only this sitting Same method, other sittings
This one has only struck here so far.
73 Carbon cycle diagrams: follow the arrows and check each product for carbon and hydrogen Key method Biology Ecology & Plant Physiology 2 other sittings Same method, other sittings
74 Osmosis moves water toward the more concentrated solution The three osmosis definition traps examiners plant in statements Rate of diffusion or osmosis is set by the steepness of the gradient Pavlov Biology Membrane Transport, Cell Division & Reproduction 7 other sittings Same method, other sittings
75 Could, may or might means find one valid scenario, not prove it always holds The genetic code is degenerate: a base change need not change the amino acid or the phenotype Key method Biology DNA, Protein Synthesis & Gene Technology 3 other sittings Same method, other sittings
76 Counting alleles across a pedigree: body cells are diploid, mind the sex chromosomes Tunnel Biology Inheritance, Variation & Evolution 2 other sittings Same method, other sittings
77 DNA structure recall: a nucleotide is phosphate plus sugar plus base, and the backbone alternates sugar and phosphate Pavlov Biology DNA, Protein Synthesis & Gene Technology 1 other sitting Same method, other sittings
78 Breathing mechanics and the sign of the intrapleural pressure Pavlov Biology Animal Physiology: Systems, Homeostasis & Disease 1 other sitting Same method, other sittings
79 Synapse transmission is chemical, by diffusion, and slower than the axon Pavlov Biology Animal Physiology: Systems, Homeostasis & Disease 1 other sitting Same method, other sittings
NSAA 2023 Section 1 Part B (ESAT Physics) 20 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 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
41 Pick the rate reason: collision frequency versus collision energy Pavlov Chemistry Rates of Reaction & Energetics only this sitting Same method, other sittings
This one has only struck here so far.
42 Addition-polymer repeat unit: two backbone carbons, side groups kept Key method Chemistry Organic Chemistry, Separation & Analysis 2 other sittings Same method, other sittings
43 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
44 Judge a reaction as redox from its type before assigning oxidation numbers Ionic equations keep only the ions that change; spectators do not affect mass or rate Key method Chemistry Chemical Reactions, Acids, Bases & Redox 5 other sittings Same method, other sittings
45 Ion charges fix the formula, the reacting ratio and the number of ions Pavlov Chemistry Quantitative Chemistry 2 other sittings Same method, other sittings
46 Classify the structure and bonding, then read off the property Key method Chemistry Atomic Structure, Bonding & the Periodic Table 6 other sittings Same method, other sittings
47 Electron configuration gives the Period, the Group and the element Pavlov Chemistry Atomic Structure, Bonding & the Periodic Table 2 other sittings Same method, other sittings
48 Read a nuclide symbol into protons, neutrons and electrons Pavlov Chemistry Atomic Structure, Bonding & the Periodic Table 5 other sittings Same method, other sittings
49 Ion charges fix the formula, the reacting ratio and the number of ions Reactivity series reflex: a metal below hydrogen gives no reaction with dilute acid, a more reactive metal displaces a less reactive one Pavlov Chemistry Quantitative Chemistry 3 other sittings Same method, other sittings
50 Bond-energy balance: broken minus formed, counting every bond Exploit the bond-energy option list: sign, factor and phantom bonds Tunnel Chemistry Rates of Reaction & Energetics 4 other sittings Same method, other sittings
51 Molar gas volume both ways, and the two traps: cubic decimetres versus cubic centimetres, and diatomic gases Pavlov 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 Electron configuration gives the Period, the Group and the element Oxide formula and acid-base character straight from the group Tunnel Chemistry Atomic Structure, Bonding & the Periodic Table 6 other sittings Same method, other sittings
53 Oxidation states sum to the overall charge, capped by the group number Key method Chemistry Chemical Reactions, Acids, Bases & Redox 2 other sittings Same method, other sittings
54 Strong versus weak acid: only the hydrogen ion properties differ, not the amount of acid Neutralisation counts protons and hydroxides per formula unit, not acid strength Key method Chemistry Chemical Reactions, Acids, Bases & Redox 4 other sittings Same method, other sittings
55 Calorimetry: q equals mc delta T, then divide by the limiting moles Tunnel Chemistry Rates of Reaction & Energetics 3 other sittings Same method, other sittings
56 Track the bulk solution, not just the electrodes: concentration and pH changes Key method Chemistry Electrolysis & Metals 2 other sittings Same method, other sittings
57 The mole bridge: convert mass, gas volume and particle count to moles Alkene addition: one atom to each double-bond carbon, one molecule per bond Tunnel Chemistry Organic Chemistry, Separation & Analysis 2 other sittings Same method, other sittings
58 Read the reactivity order off the behaviour, do not recall a fixed list Key method Chemistry Electrolysis & Metals 2 other sittings Same method, other sittings
59 Purity and hydration are just multiplying factors: scale in the right direction and the pre-scaled value is the trap Key method Chemistry Quantitative Chemistry 2 other sittings Same method, other sittings
60 Combustion by general formula: balance carbon, then hydrogen, then oxygen, counting the fuel's own oxygen Tunnel Chemistry Chemical Reactions, Acids, Bases & Redox 2 other sittings Same method, other sittings
NSAA 2023 Section 1, Part A (Mathematics questions) 18 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
1 3D solids: equating volumes and surface areas algebraically Tunnel Pure Geometry 5 other sittings Same method, other sittings
3 Rearranging Complex Formulas Pavlov Pure Algebra, Functions & Graphs 4 other sittings Same method, other sittings
4 Convert means into absolute totals Pavlov Prob & Stats Probability & Statistics 4 other sittings Same method, other sittings
5 Overlay a coordinate system for complex intersecting shapes Key method Pure Geometry 5 other sittings Same method, other sittings
6 Algebraic Fraction Simplification Pavlov Pure Algebra, Functions & Graphs 6 other sittings Same method, other sittings
7 Reduce exponential equations to a single prime base Pavlov Pure Number & Units 3 other sittings Same method, other sittings
9 Pick a convenient starting value for pure ratio and percentage problems Key method Pure Ratio & Proportion 1 other sitting Same method, other sittings
10 Non-standard trig ratios: scale a base right-angled triangle Key method Pure Geometry only this sitting Same method, other sittings
This one has only struck here so far.
11 Average speed is total distance over total time, never the mean of speeds Pavlov Pure Number & Units 1 other sitting Same method, other sittings
12 Implicit line equations: isolate y to find the gradient safely Pavlov Pure Coordinate Geometry 3 other sittings Same method, other sittings
13 Scaling laws for similar figures and solids Pavlov Pure Ratio & Proportion 4 other sittings Same method, other sittings
14 Setting up the proportionality constant Tunnel Pure Ratio & Proportion 5 other sittings Same method, other sittings
15 Factor out surds before expanding or rationalising Key method Pure Number & Units 2 other sittings Same method, other sittings
16 Minimum of a Quadratic Pavlov Pure Algebra, Functions & Graphs 2 other sittings Same method, other sittings
17 Coordinate transformations algebraically Key method Pure Geometry 3 other sittings Same method, other sittings
18 AP Conditions to Linear Relations Tunnel Pure Sequences & Series 1 other sitting Same method, other sittings
19 Common Exponent → Single Base Key method Pure Exponentials & Logarithms only this sitting Same method, other sittings
This one has only struck here so far.
20 Set up algebraic probability trees Tunnel Prob & Stats Probability & Statistics 4 other sittings Same method, other sittings
NSAA 2023 Section 1, Part C (Chemistry questions) 10 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 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
21 Factor and Remainder Theorem Pavlov Pure Algebra, Functions & Graphs 3 other sittings Same method, other sittings
23 AP Conditions to Linear Relations Tunnel Pure Sequences & Series 1 other sitting Same method, other sittings
25 Discarding the Extraneous Root Three Consecutive Terms Equation Key method Pure Sequences & Series 3 other sittings Same method, other sittings
27 Circle theorems: angle chasing Tunnel Pure Geometry 2 other sittings Same method, other sittings
29 Minimum of a Quadratic Pavlov Pure Algebra, Functions & Graphs 2 other sittings Same method, other sittings
31 Symmetric Limits and Even Functions Pavlov Pure Integration 1 other sitting Same method, other sittings
33 Rewriting Before Differentiating Pavlov Pure Differentiation 1 other sitting Same method, other sittings
35 Logarithmic Equations → Equating Arguments Tunnel Pure Exponentials & Logarithms only this sitting Same method, other sittings
This one has only struck here so far.
37 Look Ahead in Binomial Expansions Key method Pure Sequences & Series 2 other sittings Same method, other sittings
39 Extremes on a circle: use geometry, not calculus Key method Pure Coordinate Geometry 1 other sitting Same method, other sittings
NSAA 2023 Section 1, Part D (Biology questions) 20 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 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
21 Answers given as formulas: settle them by units and by which symbol already carries g Key method Physics Energy, Work & Momentum 1 other sitting Same method, other sittings
22 Pick the SUVAT equation that skips the variable you were not asked about Average force over a non-uniform phase is the momentum change divided by the time Tunnel Physics Kinematics & Forces 2 other sittings Same method, other sittings
23 Find the current first: it is the hub of every electrical chain Choose the power formula by the shared quantity, then split power as R or as one over R Pavlov Physics Electricity & Magnetism 5 other sittings Same method, other sittings
24 Label the circuit with the two invariants, then carry the one given number across In a two state question, lock the invariant from state one before touching state two When the resistances are identical or never given, call each one R and let it cancel A closed ideal switch is a plain wire: redraw before you compute Tunnel Physics Electricity & Magnetism 7 other sittings Same method, other sittings
25 Distance, displacement and average speed are three different readings of the same motion Pavlov Physics Kinematics & Forces 3 other sittings Same method, other sittings
26 Springs: the extension is not the length, and the stored energy is half of what you expect Key method Physics Energy, Work & Momentum 3 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 Let the option list choose your units, and kill options by dimensions Turn what you are given into a mass before you divide by a volume Turning a solid onto another face changes the area, never the weight Key method Physics Matter 5 other sittings Same method, other sittings
29 A mirror rotated by an angle turns the reflected ray by twice that angle, and parallel mirrors keep the ray direction Key method Physics Waves, Sound & the Electromagnetic Spectrum only this sitting Same method, other sittings
This one has only struck here so far.
30 Half-life arithmetic: work in powers of one-half, never in logarithms Pavlov Physics Radioactivity 5 other sittings Same method, other sittings
31 Which graph or what is happening: write the expression in each regime, then argue slope and curvature Key method Physics Kinematics & Forces 1 other sitting Same method, other sittings
32 Layers in series carry the same heat flux, so the temperature drops most across the worst conductor Key method Physics Thermal Physics only this sitting Same method, other sittings
This one has only struck here so far.
33 Ice and water mixtures: test the melting budget before writing any equation Key method Physics Thermal Physics 1 other sitting Same method, other sittings
34 Transformers: voltage by turns ratio, current by power, never turns ratio for a non ideal current Tunnel Physics Electricity & Magnetism 3 other sittings Same method, other sittings
35 Across a boundary the frequency is fixed, so speed and wavelength change together Pavlov Physics Waves, Sound & the Electromagnetic Spectrum 2 other sittings Same method, other sittings
36 Total path of an oscillating particle is four times the amplitude per cycle Key method Physics Waves, Sound & the Electromagnetic Spectrum 3 other sittings Same method, other sittings
37 Force on a current: the work is deciding what B, I and L really are Key method Physics Electricity & Magnetism 4 other sittings Same method, other sittings
38 Read the option spread before computing: the distractors name the slip Key method Physics Electricity & Magnetism 4 other sittings Same method, other sittings
39 Free body first: list every force with its sign, then set the resultant equal to ma Steady motion is a free equation, and after a perturbation only the change is unbalanced Tunnel Physics Kinematics & Forces 4 other sittings Same method, other sittings
40 Trapped gas: build the absolute pressure first, then apply Boyle's law Tunnel Physics Matter 2 other sittings Same method, other sittings
