Sodium is an example of an alkali metal. The alkali metals are found in the leftmost column of the periodic table, known as Group 1. Use the interactive periodic table to explore the properties of the following alkali metals: lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs). The animations demonstrate a chemical property common to alkali metals: they react with water. How does the reactivity vary among this group of elements? Why might patterns like this be useful to scientists?