Make a list of 6 – 10 things that you know or think you know about water. These things can include any unique characteristics or properties.

Water is the solvent of life Objective 1: Explain the properties of water at a conceptual level

The unique properties of water: Polar Molecule Cohesion/Adhesion Universal Solvent

In a water molecule, the oxygen is more electronegative than hydrogen 1. Polar covalent ~ water In a water molecule, the oxygen is more electronegative than hydrogen Oxygen has a slight negative charge partial negative Hydrogen has a slight positive charge and are pulled toward O partial positive

2. Cohesion/Adhesion: Cohesion is the ability of water molecules stick together Adhesion is the ability of water molecules to stick to other to other surfaces

What is Surface Tension? Surface tension- the ability for water to resist external forces on the molecules Ex: why water striders are able to look like they are “floating” Look ma’ I'm walking… Surface tension- the ability for water to resist external forces on the molecules Ex: why water striders are able to look like they are “floating” SURFACE TENSION

3. Universal solvent Water is the universal solvent. This means it can dissolve nearly everything. This polar molecule allows it to become attracted to many other kinds of molecules.

Another unique property of water…Hydrogen bonding Hydrogen atoms in one polar covalent molecule are attracted to an electronegative atom in another polar molecule This creates H-bonds Draw this picture in NOTEBOOK

Objective 2: Explain how water's properties are essential for life on Earth

Why water being a universal solvent is essential to life: Since water is the universal solvent, it can dissolve practically anything When water dissolves a chemical, nutrient, or mineral, it carries these important compounds with it Water thus serves as a vehicle to carry important chemicals & nutrients to living things

Why Water’s Polarity matters: Because of water being polar, H20 molecules exhibit great surface tension. Surface tension: the ability of water to resist external forces; this is why bugs look like they can “walk” on water The surface tension leads to providing organisms with water

Objective #3: Provide examples of properties of H2O that are essential for life.

Water has high surface tension Example: Water’s high surface tension allows water to move through plants and stems Another example: High surface tension allows water to travel along blood vessels (as one molecule moves it pulls the others with it)