1. P ROPERTIES OF W ATER Applied Chemistry

2. I.Introduction to Water A.Water is a common substance on Earth, but is one of the rarest and most unusual substances in the universe B.About 70% of Earth’s surface is covered by oceans more than 2 miles deep C.Water is the only natural substance that is found in all three states of matter : solid (ice), liquid, and gas (steam)

3. II.Physical Properties of Water – properties that can be observed and measured, without changing the chemical makeup of a substance A.Density - a measure of the mass of a material in a given volume  Because 1 milliliter (mL) of water has a mass of 1 gram (g), water’s density is 1.00 g/mL B.Freezing Point: 0 O C at normal pressure Boiling Point: 100 O C at normal pressure C.Pure water is clear, colorless, odorless, and tasteless

4. III.Chemical Properties of Water – properties that are observed or measured during or after a chemical reaction A.Water is a compound – a substance composed of 2 or more elements linked together chemically by bonds 1. Water is also a molecule – it’s atoms are chemically linked by covalent bonds, meaning the atoms share electrons 2.2 hydrogen atoms for every 1 oxygen atom (H 2 O) B.Water has a pH of 7 – it is neutral  neither acidic, nor basic

5. C.Water is Polar – it has a positive charge near the H atoms and a negative charge near the O atom  Because opposite charges attract, water molecules tend to attract each other, making water kind of “sticky” creating:  Adhesion, Cohesion, Surface tension, and Capillary action D.Water dissolves other polar molecules (solutes), making it the “universal” solvent 1.wherever water goes, it takes along valuable chemicals, minerals, and nutrients CrashCourse Biology – Water: Liquid Awesome