Water is necessary for life. This makes it is a precious and unique resource here on Earth – and not just for humans. Water is necessary for all forms of life on Earth. As humans, we use water all the time. We drink it. We bathe in it. We swim in it. We use it for cooking, cleaning, manufacturing, and so much more. Our bodies are even made up mostly of water! Water is essential to life, but do you really know much about it? We’ve rounded up a list of facts about water so that you can learn more about this critical resource. Read on to see all the cool facts about water!
#1 Only 1% of Earth’s Water Is Currently Usable.
Nearly 97% of the world’s water supply is salty or otherwise undrinkable. Another 2% of Earth’s water is locked in ice caps and glaciers. Only 1% of the world’s water supply is available for meeting humanity’s needs. These include agricultural, residential, manufacturing, community, and personal needs.
#2 Most of Earth’s Fresh Water Is Frozen.
Only 3.5% of the water on Earth is fresh water. This type of water contains little salt and can be found in lakes, rivers, and streams. However, the majority of Earth’s fresh water is locked in ice and glaciers – over 68% of it, in fact! Another 30% of Earth’s fresh water is located in groundwater.
#3 The Saltiness of Salt Water Varies.
Typically, in a gallon of ocean water, there is about 1 cup of salt present. However, the amount of salt in salt water can vary. For example, the Atlantic Ocean is saltier than the Pacific Ocean. However, most of the salt in salt water is the same – sodium chloride, which is the same type of salt that we put on our food. Wondering where the saltiest water in the world is located? It’s found in a small lake in Antarctica, called Don Juan Pond.
#4 Water Expands When It Freezes.
Water expands by about 9% when it freezes; rather than drawing closer together, its molecules form rings. This is unusual because most substances get denser in solid form – not less dense. The fact that frozen water (ice) is less dense means that ice is lighter than water in its liquid form. The difference in density is why ice floats in water.
#5 There’s a Good Chance That Dinosaurs Drank the Same Water You’re Drinking Right Now.
The water on Earth today is the same water that’s been on Earth for nearly 5 billion years. Only a small amount has escaped out into space, and as far as we know, no new water has formed. This means that there’s a high chance that the water in your glass contains some of the same water molecules that dinosaurs drank 65 million years ago!
#6 Water Can Dissolve More Substances Than Any Other Liquid.
Water is often referred to as the “universal solvent” because it can dissolve more substances than any other liquid – even more than sulfuric acid! Water’s chemical composition and physical attributes are what make it such an effective solvent. Since water molecules have a polar arrangement of oxygen and hydrogen atoms and one side has a positive charge while the other has a negative charge, water molecules are capable of becoming strongly attracted to many different types of molecules, so much so that the water molecules can disrupt the attractive forces that hold other compounds together. This is how water is able to dissolve so many substances.
#7 Hot Water Sometimes Freezes Faster Than Cold Water.
Under certain conditions, hot water can freeze faster than cold water. This is called the Mpemba effect. There are many theories for why this phenomenon occurs, but scientists have not yet definitely proven why it happens. The Mpemba effect is named for a 1960s schoolboy from Tanzania named Erasto Mpemba, who claimed that ice cream would freeze faster if it was heated before being placed into the freezer. A school official tried the experiment himself and realized Mpemba was right.
#8 The ISS Has 2 Different Water Systems.
Because there is no naturally occurring drinkable water on the International Space Station (ISS), humans have to make their own. The ISS is currently split into two sections; one is run by Russia and one is run by the United States. Each side uses a different water system. The U.S. system collects condensate, runoff, and urine to create about 3.6 gallons of drinkable water per day. The Russian system collects only shower runoff and condensate to create slightly less than 3.6 gallons of drinkable water per day.
#9 The Human Brain Is 75% Water.
You might be surprised to learn that 75% of your brain is water. This means that even a small amount of dehydration can have a negative effect on brain functions such as memory and attention.
#10 The Human Body Is Mostly Water, Too.
Humans are extremely dependent on water. Newborns are about 78% water. Adult bodies are 55% - 60% water. In fact, water is involved in almost everything human bodies do. Water plays a role in getting rid of waste in the body, regulating body temperature, acting as a shock absorber for the brain and spinal cord, and much more.
Want to learn more cool facts about water? Then check out this video!
Want to learn even more about the world around you? Check out our roundup of 8 awesome facts about trees!