Water, is the essence of life. It is the substance that nourishes of the body
and soul. A colorless, tasteless and odorless liquid that shapes three-quarters
of planet earth’s surface area, with the absence of it, a human body can die
within three days. We use water on a daily basis. We cook, clean, shower, water
our gardens, transport by seas and oceans and many more activities that exist
due to the presence of water. It is made of a covalent compound that shares the
electrons of two hydrogen and oxygen atoms. It is recognizable at its three
states, solid (ice), liquid (at room temperature) and gas (steam or water vapor).
Water has various, very unique physical
properties as a result of its molecular configuration. Some of which include; its
expansion upon freezing, its surface tension and its interaction with light.
Surface tension is a force that creates a
protective lawyer on the surface of water which enables the resistance of an
external force such as gravity it is caused by water’s surface molecules’
cohesive nature in which there are bonds between water molecules (hydrogen
bonds). An example of surface tension is washing your hands. When washing your
hands water molecules’ surface tension isn’t broken as a result the water doesn’t
go to all grooves or indentations however adding soap causes that tension to
break leading to a more thorough cleansing process.
of a water molecule consists of two hydrogen atoms and one oxygen
atom. The oxygen atom is negatively charged however the hydrogen atoms are positively
charged. The opposite charges lead to the formation
of hydrogen bonds. These bonds get stronger at
lower temperatures due to the decrease in thermal energy that cause movement. When
water converts to ice by being 4o or less, the hydrogen bonds hold
the water molecules in a hexagonal lattice that is full of holes.
Water as a liquid is moving and disordered while as a
solid it is static and ordered with more space between molecules. The most stable water structure has more
space so it’s less dense. When ice melts the molecules gain energy and start moving around constantly.
This movement redistributes the hydrogen bonds, bringing them closer, thus,
water becomes denser.
The open solid lattice structure leads
to ice’s lower mass per volume (density), which allows it
to float on water. This is a very lucky feature for the aquatic
environment. For example, if a
pond with living fish in it freezes and the water didn’t expand upon freezing then the colder denser
water would sink down and the pond would freeze from the bottom up leading to the fish swimming on the surface which may eventually kill
them. If water behaved like other liquids then
consequently many bodies of water would freeze
solid in the winter, killing all the life within them. However water isn’t
the only substance that expands when it freezes, others include; Gallium,
Germanium, Acetic acid, Silicon and Plutonium.