Potassium

Potassium is a soft metal that can easily be cut with a knife. It’s very reactive, and causes an explosion when mixed with water! It’s silvery-white in colour, but quickly turns grey when it touches oxygen in the air. To stop this, the metal is stored in oil which stops it reacting with air.

You can’t go looking for potassium metal like gold prospectors did during the gold rush. This is because pure potassium metal doesn’t occur naturally in nature because it reacts straightaway with water to form a different compound.

When experiments are done with potassium, you have to protect your skin and eyes because the reactions are explosive. When potassium reacts with water lots of heat is given off, which ignites hydrogen to produce a bright lilac flame. Because of this it’s also used to make fireworks and matches.

Potassium is very similar to sodium, and scientists didn’t even realise they were different metals until 1807. Nowadays, potassium has a bit of a hard deal as it’s been replaced by sodium in most chemical reactions. However potassium is still used in the production of fertiliser as plants need potassium to grow. Potassium allows the opening and closing of stomata (gaps between plant cells) which control energy gain through photosynthesis, and water loss. Over 90% of potassium produced is used in fertilisers – that’s a lot of happy healthy plants.

If humans don’t have enough potassium our brains and muscles can stop working properly. This is another reasons to eat your greens – lots of potassium is found in fruit and veg such as potatoes, bananas, avocados and broccoli.