How to Pass 13 plus Common Entrance Science (Part 1: Mastering the basics)

Phil is a tutor with Owl Tutors


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September 9th, 2019

How to Pass 13 plus Common Entrance Science (Part 1: Mastering the basics)

In this blog, Phil, an experienced school entrance tutor, sets out how students can ensure success at 13 Plus Common entrance Science. Mastering the basic theories, equations and laws is essential and Phil provides a helpful list of topics which simply must be memorised by 13 Plus candidates. This is the first of a two part series.

The first thing to keep in mind is that there is no formal pass mark. Individual schools decide on their own thresholds and so what constitutes an “A*” at one school may only be a “B” at another. The minimum expectation stands around the 55% mark and for the most competitive and highly rated schools, pupils need to score over 70%. Some pupils may struggle with a particular discipline of science more than the other two and so, even if the pupil is never going to score highly in the Physics paper (for example), the average of the three sciences will be taken into account. Equally should they excel in the Chemistry paper, then this will compensate for any lower scores elsewhere.

So, what is my advice on how to succeed?

Learn the basics

In each of the sciences there are certain ideas that simply must be learnt by heart. I hate to say it, but even if there is no clear understanding, just to know “the facts” should still guarantee marks as these types of question crop up time and time again (albeit in slightly different contexts). For example, in Physics there will always be one or more questions simply asking for a formula (point 1 of the physics list below). If they then struggle to confidently use the formula, then sadly those are lost marks but at least the student has banked at least one mark! Without a secure knowledge of the basics the higher order questions will pose huge issues.

Below are examples for each of the sciences of topics that I feel simply must be learnt to guarantee success at 13 Plus.   In a later blog, I will provide advice around revision and exam technique.  


In Biology, students must know: 

  • The respiration equation: Oxygen + glucose = carbon dioxide + water (+ energy)
  • The Photosynthesis equation: carbon dioxide + water = oxygen and glucose (chlorophyll and light needed)
  • The key features of the gas exchange at alveoli: thin, moist and large surface area
  • That discontinuous variation (distinct differences which can be grouped, ie eye colour) is due to genes only whereas continuous variation is due to genes and the environment, ie height, weight.
  • That methylene blue is stain used for microscope viewing of a cell and iodine solution for the starch test (turns blue / black)
  • The 7 food groups – water, fibre, protein, vitamins, minerals (iron, calcium etc), carbohydrates, fat (and examples of each and types of food that provides each)


In Chemistry, students must know:

  • The chemical test for water – Anhydrous copper sulphate turns from white to blue
  • The chemical tests for gases:
    • Hydrogen = squeaky pop
    • Oxygen = glowing splint
    • Carbon dioxide = limewater turns cloudy
  • That burning a hydrocarbon (a fuel which is made up solely of hydrogen and carbon atoms such as methane) is an oxidation reaction, so fuel + oxygen = carbon dioxide + water (+ energy) which is exactly the same as respiration in Biology!
  • The definition of a compound: two or more elements chemically bonded together
  • The definition of an element: a substance made up of one type of atom only
  • That a decomposition reaction is using heat to break down a compound into simpler substances and the common compounds to be aware of (and always associate with decomposition if they crop up) are:
    • calcium carbonate = calcium oxide + carbon dioxide
    • Copper carbonate = copper oxide + carbon dioxide
    • Potassium permanganate = oxygen + other compounds
  • That the equation for rust is: water + oxygen + iron = hydrated iron oxide (rust)
  • That air is a mixture made up of about 80% nitrogen, 20% oxygen (plus other trace gases)
  • That sulphur dioxide (from burning coal) is main gas associated with acid rain
  • That Universal indicator measures pH (or how strong an acid or alkali is). Red meaning very strong (1pH), green meaning neutral (7pH) and violet/purple meaning strong alkali (pH14).
  • The 3 acid / neutralisation reactions:
    • metal + acid = salt + hydrogen (ie Magnesium + hydrochloric acid = magnesium chloride + hydrogen)
    • Base + acid = salt + water (ie sodium hydroxide + hydrochloric acid = sodium chloride + water)
    • Carbonate + acid = salt + water + carbon dioxide (ie calcium carbonate + sulphuric acid = calcium sulphate + water + carbon dioxide)


In Physics, students must know: 

  • The key formulae (and the various units of measure):
    • Density (g/cm3)= mass / volume
    • Pressure (N/cm2) = force / area
    • Moments (Nm) = force x distance from pivot
    • Speed (m/s) = distance / time
  • That magnetic field lines travel from north to south
  • That an LED uses low current and works in one direction only
  • That electromagnets can be made stronger by: adding more coils, increasing the current, using an iron core
  • The order of the planets: mercury, venus, earth, mars, Jupiter, Saturn, Uranus, Neptune (Pluto) – my very eccentric mother just shot uncle norman’s pig…
  • That if forces are balanced either the object is moving at a CONSTANT SPEED or is STATIONARY. If forces are unbalanced either the object is SPEEDING UP or SLOWING DOWN.
  • That the angle of incidence = the angle of reflection in light diagrams
  • That high frequency sounds = high pitch (lots of vibrations on the oscilloscope pattern). Low frequency sounds = low pitch (very few vibrations in comparison on the oscilloscope pattern). Amplitude is the loudness of a sound and depends on the energy put into the vibration (high tall or short the vibrations are on the oscilloscope pattern)

Mastering these basics will stand you in very good stead and provide a solid foundation for exam success.  Next, a thorough revision plan and good exam technique will get you over the line! 

Read my next blog: How to Pass 13 plus Common Entrance Science: Part 2

Phil is a tutor with Owl Tutors

More about Phil

Phil qualified as a teacher in Primary education in 2002, and now works as a tutor with Owl Tutors.

Phil is a full-time online tutor with Owl Tutors, specialising in Common Entrance 11+ and 13+ Science and Maths. After 14 dedicated years in the classroom, latterly at Westminster Cathedral Choir School as Head of Science, he is now living in Worcester where he is undergoing a big house project / renovation.