Properties of Water 1
Properties of Water
What Makes Water So Special?
When you hear that NASA’s space probes are looking for “evidence of life” on other planets, do you know
what that means? They are looking for evidence of liquid water. Water is fundamental for all life; without
it every living thing would die. Water covers about 70% of Earth’s surface and it makes up 65–75% of our
bodies (82% of our blood is water). Even if water might seem boring to you—no color, taste, or smell—it
has amazing properties that make it necessary for supporting life.
Model 1 – The Molecular Structure of Water
= electron presence
Electron density model of H
1. How many hydrogen atoms are in a molecule of water?
2. How many oxygen atoms are in a molecule of water?
3. What holds the hydrogen atoms to the oxygen atom?
4. The shading around the molecule represents the relative density of electrons shared by the atoms.
What does this indicate about the density of electrons around the oxygen atom as compared to
the density of electrons around the hydrogen atoms?
5. Where is the majority of negative charge on the water molecule?
The oxygen atom has a slight negative charge-
electrons are attracted to it. It ismore dense around the oxygen atom and less dense around the hydrogen atoms.