1. Properties of Water
TSW describe the properties of water that make it essential to life on Earth

2. What is water?
H2O…which means? 1 molecule of water has 2 atoms of Hydrogen & 1 atom of Oxygen
Water covers up to 75% of the Earth’s surface & makes up 70-95% of all living cells!

3. Atomic Structure 2H + O → H2O
Each Hydrogen atom is held onto the Oxygen atom by a polar covalent bond

4. Let’s take it a step further…
Hydrogen
Protons: 1
Neutrons: 0
Electrons: 1
Oxygen
Protons: 8
Neutrons: 8
Electrons: 8

5. Types of Bonding
Ionic
Covalent
Polar Covalent
Hydrogen

6. Ionic Bonding
Forms when 1 or more electrons are transferred from one atom to another
If P > E → (+) charge
If P < E → (-) charge
Example: NaCl

7. Covalent Bonding
Forms when electrons are shared between atoms NOT transferred, the resulting structure is called a molecule
Example: HCl or H2

8. Polar Covalent Bonding
Forms when sharing occurs in an unequal manner (the molecule formed has no net charge)
Opposite ends of the molecule are partially (-) & partially (+) depending on the distribution of electrons
Example: H2O

9. Good to know… Covalent bonds are stronger than ionic bonds
Covalent bonds do not dissociate in water

10. Hydrogen Bonding Forms between water molecules H+ bonds to O-
Easy to break
Key Point: The numerous special qualities of water are made possible by its ability to form multiple H bonds