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This year, for science, we’ve learnt many things. Last term, for Year 8 Science, we learnt about chemical reactions. They’re much more complicated and interesting than you might think. There are many more chemical reactions than most people know about. For example, there are neutralisation reactions, metal and acid reactions and more. But, what are they? To understand that, there’s some context. Firstly, the pH scale. The pH scale is a scale for how acidic or alkaline a substance is. It is from 1-14, and where a substance is on the scale can determine many properties of that substance. For example, a pH 1 substance, like battery acid, will be very corrosive and harmful to organic matter, like skin. But a pH 14 substance, like drain cleaner, isn’t any better. A strong alkali is very similar to a strong acid in terms of properties. They are both very corrosive, or eat away at material, and are harmful. But a weaker acid might just taste a bit sour, like vinegar, coffee and even milk. And a weaker alkali would have a bitter taste and a soapy touch. Soap is an alkali, bleach is an alkali - but soap is a weak alkali, and bleach is a strong alkali.
But back to chemical reactions. A neutralisation reaction is when you get an alkali and an acid, and you put them together. The result will be a salt and water. A salt will be created in this reaction, but not table salt. The only edible salt is NaCl, Sodium Chloride. A salt is named using a metal and the end of an acid, of which there are 3. Hydrochloric acid, Nitric acid and Sulphuric acid. A salt created with hydrochloric acid will end in chloride, one created with nitric acid will be called a nitrate and one created with sulphuric acid will be called a sulphate. And water is just your standard H20, the same drink that keeps you alive everyday.
But there are other reactions too. For example, a metallic and acidic reaction, like reacting Sodium and Hydrochloric acid would create a Sodium Chloride (or table salt) solution. A metallic and acidic reaction = M.A.S.H. Metal, Acid, Salt, Hydrogen. A metal+acid—>salt+hydrogen.
And even after this, there’s more! You have to write these reactions in very key ways. Namely, as a word or symbol equation. A word equation might be like magnesium+oxygen—>magnesium oxide. But a symbol equation uses the symbols from the periodic table, so the same equation would be Mg+O—>MgO.
The thing to remember about this whole topic is that science is amazing. It is the building blocks of life, it is what underlies all of the universe, and fascinates millions of people, and it will continue to do this. It encourages us to be curious, inquisitive and knowledgeable. It tests our brains, which makes it so enjoyable! And it has and will continue to help people all over the world, forever.
Dilan Shah - Year 8 Science Prefect
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