Interesting facts about water
Water is sticky
Water molecules love to stick to things – especially each other. This is why water has a large surface tension and if you carefully fill a glass of water beyond its rim, the water will actually hold its shape beyond the rim of the glass before gravity causes it to overflow. The stickiness of water is the only reason that water is a liquid at room temperature – it should actually be a gas when you compare it to other similar molecules like hydrogen sulphide (H2S) and ammonia (NH3), which are both gases at room temperature.
Water comes from out of space
All water arrived on the planet around 4.5 and 3.8 billion years ago in comets and asteroids. Today 97% of water is salty and only 1% is available as fresh drinking water. There is ice on the poles of the moon and on the poles of Mars and Mercury.
The water levels in your body vary
When you are a foetus in the womb, your body consists of around 95% water, by the time you are born this has dropped to 77% and by the time you are an adult, this has dropped even further with a 70kg person having around 42 litres of water in their body. When you are younger you also need more water than when you are older and children in the first six months of life consume seven times more water per kilogram than the average adult.
Hot water freezes faster than cold water
Unlike most other liquids, water expands around 9% when it freezes.
Water is denser than oil
The molecules that make up oil are larger than those that make up water, but this means they cannot pack as tightly together which means they take up less space per unit, resulting in oil being less dense than water.
Water can intoxicate you
If you drink too much water in a short time, you can cause the levels of sodium in your blood to drop too low – which can be fatal!
The world is running out of fresh water
If we decreased the entire world’s water to fit into a 4-litre jug, the fresh water available for us to consume would only take up one teaspoon and the amount of usable fresh water that is easily accessible is declining due to:
- The increased food requirements of a growing population
- Increased energy requirements of a growing population
- Increased frequency of droughts, which are diminishing fresh water supplies
- In many parts of the world groundwater is being pumped out and used faster than it is being replenished
- Inadequate water infrastructure is resulting in millions of litres of fresh water being lost