Student Question

Expert Answers

An illustration of the letter 'A' in a speech bubbles

Water is a molecule that contains two atoms of hydrogen and one atom of oxygen. It can exist as a solid, liquid or gas on Earth, depending on the temperature. It covers 70.9 percent of Earth's surface. Living things depend on water to survive. The oxygen atom has a slight negative charge relative to the two hydrogens atoms which are slightly positive, making water a polar molecule. There are strong attractive forces between water molecules. This accounts for capillary action, when water molecules can move up a narrow tube, against the force of gravity, allowing it to travel upwards from roots, to stems to leaves, in the xylem tubes of conducting tissue in plants. It is a universal solvent and important substances for living things such as salt, sugar, acid, alkalis and gases as well as protein, DNA and polysaccharides, can dissolve in it.

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Approved by eNotes Editorial