During a science demonstration, a teacher decides to show students the reaction of sodium (an alkali metal) with water. What do you expect to happen during this reaction, and why is it significant in understanding the properties of alkali metals?

When sodium touches water, it reacts violently, producing sodium hydroxide, hydrogen gas, and a bright flash of light and heat. The sodium atoms give up their single outer electron to the water molecules, forming Na⁺ ions and releasing hydrogen gas, which ignites because of the heat. This shows that alkali metals have one loosely held electron that is easily lost, making them highly reactive and capable of strong, exothermic reactions. Seeing this reaction helps students see why alkali metals are soft, shiny, and extremely reactive with water, a key trait that distinguishes them from other metals.