Student Article
Understanding Water: The Key to Life on Earth
Hydrogen bonding (noun): The attraction between hydrogen atoms and other molecules, making water molecules stick together.
Solvent (noun): A substance that can dissolve another substance, like water dissolving salt.
Evaporate (verb): Change from liquid into a gas, usually because of heat.
Precipitation (noun): Water falling from the atmosphere to Earth, such as rain or snow.
Water, one of the most essential substances for life, covers over 70% of Earth’s surface. Its unique properties have made Earth the only known planet to support life as we understand it.
A one-of-a-kind molecule
Water, chemically composed of two hydrogen atoms and one oxygen atom, is the only substance that exists naturally on Earth in all three states — solid, liquid, and gas. This allows water to play a crucial role in the functioning of life.
Sticky molecules that help life
One of the key properties of water is its ability to dissolve many substances, which is vital for transporting nutrients, oxygen, and waste in living organisms. This is due to the unique nature of water molecules and their hydrogen bonds. These bonds make water molecules "stick" together, a property that also causes water to have a high boiling point and freeze at a lower temperature than most liquids. This property is one reason why ice floats instead of sinking, helping life in cold environments survive.
The water cycle keeps it moving
The water cycle on Earth helps regulate and maintain life. Water evaporates from oceans and plants, rises into the atmosphere, and falls back as precipitation. This process is constantly powered by the Sun’s energy, ensuring that water circulates around the planet. Understanding the water cycle is crucial in managing Earth’s water resources.
Water in space?
In space, water has also been detected on other planets and moons, including Europa, one of Jupiter’s moons. These discoveries are changing how we think about the possibility of life elsewhere in the Universe. Water is abundant in the Universe, but its liquid form is rare, making Earth unique in supporting life as we know it.
© Brian Clegg / Our Media
Hydrogen bonding (noun): The attraction between hydrogen atoms and other molecules, making water molecules stick together.
Solvent (noun): A substance that can dissolve another substance, like water dissolving salt.
Evaporate (verb): Change from liquid into a gas, usually because of heat.
Precipitation (noun): Water falling from the atmosphere to Earth, such as rain or snow.