Density of water

This is a presentation about the Density of Water.


Coures: The Water
Unit one: The Physical and Chemical Properties of Water
Topic: Density of Water

1. The Density Of Water Course: The Water Unit: The Physical And Chemical Properties Of water. Instructor: Asma Alkhozaimi

2. Definition Of Density Density means the mass per unit volume of a substance, but on Earth you can assume mass is the same as weight. The density , also known as "specific gravity”, so as long as an object is made up of molecules, and thus has size, it has a density. Density is just the weight for a chosen amount (volume) of the material.

3. Density and Temperature Water is unique in the way temperature affects its density. Most substances increase in density as temperature decreases because the molecules making up the substance begin to move more slowly and get closer together. At to 4 degrees C , t he density of water increases and then its density begins to decrease as the temperature decreases to 0 degrees C, the freezing point of water.

4. Ice Density In the picture below, the iceberg is below the water level. Actually, almost all of the volume of an iceberg is below the water line. This is because the ice's density being less than liquid water's density. When freezing, the density of ice decreases by about 9 percent .

5. At the freezing point, hydrogen bonds relax and form a crystal lattice that keeps molecules further apart than they are in liquid water. In the Ice, the molecules align themselves in a regular lattice, while the molecules in the liquid align more randomly as in the liquid form. Therefore, the lattice arrangement allows water molecules to be more spread out than in a liquid, and, thus, ice is less dense than water. Ice Density

6. Resources Howard Perlman, U. (2014).  Water Density (water properties), USGS Water Science School . [online] Water.usgs.gov. Available at: http://water.usgs.gov/edu/density.html [Accessed 1 Dec. 2014 ]. science museum, (2014). Icebergs. [image] Available at: http://goo.gl/Ozqzew [Accessed 1 Dec. 2014].

7. The End