Fluorine is the most active element, so it combines with almost anything. Fluorides in toothpaste strengthen tooth enamel. Neon is an inert gas that glows red in neon tubes. An acid neutralizer is called a base or alkali, so sodium's group is called the alkali metals. Sodium and chlorine make salt.
Magnesium is in chlorophyll which makes plants green and enables plants to grow by using sunlight.
Aluminum is very useful because it is an abundant, lightweight metal which doesn't corrode. Silicon is one of the most common elements in rocks, sand, and dirt. Computers chips are mostly silicon. Phosphorus is one of the major elements in bones. Sulfur makes egg yolks yellow and makes rotten eggs stink.