Have you ever heard someone who was really thirsty say they needed some H2O? When someone refers to H2O, that’s actually just a nickname for water!
Water is made up of little units called “molecules.” Molecules are extremely tiny – way too tiny for you to see with just your eyes. In fact, they’re so tiny that a single droplet of water contains millions and millions of water molecules! But believe it or not, the water molecules can get even smaller! Every water molecule is made up of two units of the element hydrogen and one unit of the element oxygen! (That’s where we get the name H2O – the H2 stands for “two hydrogen” and the O stands for “one oxygen”!)
The H2O makeup of water is part of what makes water so special. The two units of hydrogen and the one unit of oxygen in each molecule of water carry a charge, with the two hydrogen each having a positive charge and the oxygen having a negative charge. It’s because of these special charges that water molecules stick to each other in the special way that lets them move and swish about, sometimes sticking together and sometimes breaking apart!
“Molecules” and “elements” might sound like fairly new ideas or things that are hard to understand, but most likely there are a few of each that you’re already familiar with!
One really good example of something common that is made up of little molecules is regular old table salt! Salt is made up of one unit of each of two elements, “sodium” and “chlorine”.
Even though there are some elements that might just seem like funny-sounding words, there are others that you are almost certainly familiar with. These probably include gold, copper, and silver, just to name a few!
Sources & links
“States of Matter: Solids.” Chem4Kids. Andrew Rader Studios. 09 Mar. 2010 “Water Properties.” 2002. Iowa Project WET: Water Education for Teachers. 09 Mar. 2010 Pidwirny, Michael. "Physical Properties of Water". Fundamentals of Physical Geography, 2nd Edition. 2006. University of British Columbia Okanagan. 09 Mar. 2010 Onken, Michael. “How many atoms are in a single drop of water?” 2000. MadSci Network. 09 Mar. 2010 “Water and its structure.” 2010. Chem1.com. 09 Mar. 2010 Periodic Table of the Elements. ChemicalElements.com. 09 Mar. 2010 "salt." Merriam-Webster Online Dictionary. 2010. Merriam-Webster Online. 9 March 2010