What Are Some of the Unique Properties of Water?

Water is a Polar Molecule What does that mean? 1) A molecule in which opposite ends have opposite electrical charges This is due the unequal sharing of electrons between the hydrogen and oxygen atoms

Why is there unequal sharing of electrons in water molecules? Because there is an uneven distribution of electrons between the oxygen and hydrogen atoms. The nucleus of Oxygen has 8 protons which pulls the electrons further from the hydrogen nucleus which only has 1 proton

Is H2 a polar molecule? No, because each of the hydrogen electrons are being pulled from an equal amount of protons. H2 is an example of a Non-Polar Molecule

Water molecules attract each other in a specific way due to this unequal sharing The slightly negative oxygen atom of one molecule attracts the slightly positive hydrogen atom of adjacent water molecules

This attraction between water molecules is called Hydrogen Bonding (4) Hydrogen Bonding is responsible for water’s unique properties

Unique Property #1 The molecules of water in ice are less densely packed than those of liquid water Therefore, ice floats in water

Unique Property #2 Cohesion- the tendency of molecules of the same kind to stick to one another Adhesion- the attraction between unlike molecules Trees depend on these properties of water to help transport water from their roots to their leaves

This is known as Transpiration Water is able to move against the force of gravity Water from the leaves evaporates and water is Pulled through the vessels in the tree from the roots

What is Surface Tension? Cohesion pulls the molecules at the surface tightly together and a filmlike boundary is formed

H bonds make water more resistant to temperature change Unique Property #3 Why does water take longer to heat up in the summer and longer to cool in the winter? H bonds make water more resistant to temperature change

Unique Property #4 Water has a great ability to dissolve other substances

**When water is the solvent, the result is called an Aqueous solution What is a solution? Solution- is a uniform mixture of two or more substances Solvent- the substance that dissolves the other substance Solute- the substance that is dissolved **When water is the solvent, the result is called an Aqueous solution