Chemistry is often considered the most difficult of the three sciences at GCSE, but with these revision tips you will be on your away to achieving top marks.
Learning the Content
Chemistry content builds on previous topics, so unless you know the fundamentals later topics can appear impossible. Start with the basics. Make sure you understand atomic structure, the periodic table and bonding. Without knowing these concepts well, GCSE Chemistry can feel like another language.
For example, how can you explain why the reactivity of group seven elements decreases as you go down the group without understanding ionic bonding to begin with?
Some key things to understand:
Atoms prefer to have a full outer shell, so will lose or gain electrons in order to fulfil this.
In the periodic table, the group (at the top) tells you the number of outer electrons and the period (at the side) tells how many shells an atom has. So sodium (Na), group 1 and period 3, has three shells and one outer electron.
The type of bond depends on whether the atoms bonding are metals or non-metals: ionic bonding; metals and non-metals, covalent bonding; more than one non-metal, metallic bonding; more than one metal. Therefore, if sodium (Na), a metal, bonds with chlorine (Cl), a non-metal, it will form an ionic bond (NaCl).
The difference between ionic and covalent bonding. Ionic bonding occurs when one atom donates or gives electrons to another atom, making them ions. The atom that has lost electrons becomes positive and the atom that has gained electrons negative. Just the same as if you were carrying lots of shopping you might feel negative, only to become more positive if someone helped and you had less to carry. The fact that one ion is now positive and the other negative means they bond together (opposites attract). Covalent is simpler, the atoms share electrons instead. This is similar to how sharing a meal with someone might cause you to bond.
Mol = Mass / Mr. Learn this equation, it comes up a lot!
“If you can’t explain it simply, you don’t understand it well enough” – Albert Einstein. Memorising the definitions and explanations only for the sake of the exam is great, but dull and time-consuming. To test your knowledge, try and explain each topic in simple terms or by using analogies. Understanding a concept well will help much more than rote-learning it. A good example of this is “moles”. Chemistry students will have heard this word a thousand times, but what does it actually mean? A mole is a word used to describe a specific quantity of something, the same as how a couple refers to two or a dozen refers to twelve. Moles are no different, but refer to a very specific number (6.02 x 1023). This isn’t very useful in everyday life, people aren’t likely to ask for a mole of bread loaves at the local bakery, but is useful for Chemistry calculations. One mole is equal to the number of atoms in one gram of an element’s atomic number, i.e. one mole of carbon = 12 grams = 6.02 x 1023 atoms.
Similarly, try explaining terms like ‘percentage yield’ to someone who has no knowledge of Chemistry. For example, if you wanted to make twelve cookies, but dropped two and burnt four, you would end up with only six cookies. This would be a percentage yield of 50% (6/12 x 100). If you don’t like Chemistry, make it about something else!
Finally, don’t make Chemistry boring on purpose. While textbooks may act as a good point of reference for your GCSE specification, make use of more engaging resources. The content of a four-hundred-page textbook with no pictures is ultimately no more valuable than a simplified, illustrated revision guide (i.e. CGP). YouTube is indispensable for GCSE revision, with channels like “Freesciencelessons” there to help you understand difficult topics in a matter of minutes. Creating a variety of condensed resources also helps. If Chemistry isn’t your thing, the GCSE course may feel dry compared to your other subjects. By making use of flashcards (or Anki) you are more likely to focus on your revision, and make progress, than by staring at the same textbook page for twenty minutes.
Past-papers, Past-papers, Past-papers
As with all exams, the key to getting top marks is completing past-papers. Even when you know the topics like the back of your hand, exams are written in a format that can throw you off. Additionally, similar questions pop up every year. You only need to complete one question on explaining fractional distillation to complete every question on explaining fractional distillation. Seeing a repeat question almost feels like cheating…
If you haven’t completed enough topics in school to have a go at full past-papers, there are websites that compile past-paper questions by individual topics. Physics and Maths Tutor and Save My Exams are great resources for testing yourself on recent areas of revision.
General Revision Tips
Chunking – People can’t learn vast amounts of information in one sitting. Revising little but often is better than trying to memorise an entire syllabus in one day.
Switch things up – If you are getting bored of a subject, you aren’t going to learn it. So, move on to something else and come back to it.
Incentives – Treat yourself when you have worked hard. This doesn’t have to break the bank, even small rewards can be motivating. Go for a walk, eat some chocolate or watch an episode of your favourite show after a few hours of revising.
The 2 3 5 7 method – Learn on day one, recap on day two and three, then test yourself on day five and seven. This may seem time consuming and can become confusing when revising lots of different topics, but the general concept still stands. You are unlikely to remember much at all from revising a topic once, it is repetition that consolidates the information to memory. Briefly return to previously revised topics, even by glancing over them a day or two later, to increase your odds for remembering them. You may wrack your brain trying to remember the name of someone you have met once, but the names of people you see daily will be with you forever. Revision is no different.
The bigger picture – Chemistry may be your favourite subject at school, or you might hate it. Either way, remind yourself of the benefits of doing well. Whether this is increasing your chances of getting into university or getting your dream apprenticeship, the end result is worth the hard work.
In the Exam
The sooner you start past-paper practice, the better. GCSEs are likely to be the first formal exams you have sat, so they can feel stressful even if you are well prepared. By completing past-papers early, under time conditions if possible, you will think more clearly in the real exam.
You don’t need 100% to get a grade 9, so don’t worry if there are questions you can’t answer. Start with the questions you are comfortable with and then move on to more difficult questions. One mistake that students make is feeling that if they won’t get to the final answer, there is no point writing anything at all. Even if you don’t think you will achieve full marks in a question, have a go at what you do know! You will be surprised at how many marks you can pick up by writing (what seems like) the obvious. f you need that extra boost prior to your exam, you know where to find us! Titanium Tutors have an array of talented Chemistry tutors on our books, and we’ll match you up with the ideal tutor to catapult you to the top of the Science scoring board.