Chlorine

chemical element · reactive gas · periodic table · strong oxidizer

Yellowy-green gas. Chlorine is a gas at room temperature that has a distinctive yellow-green color, making it one of the easiest elements to spot by sight. It sits between fluorine and bromine on the periodic table, right in the halogen family.

Super reactive buddy. Chlorine is so eager to react with other elements that it's one of the most reactive things in nature. This means it bonds with other atoms faster and more easily than almost any other element.

Electron magnet. Chlorine has the highest electron affinity of all elements, meaning it's the best at pulling electrons away from other atoms. Only oxygen and fluorine are more electronegative, making chlorine the third most powerful electron grabber around.

Keeps water clean. Because chlorine is such a powerful oxidizing agent, it's used to kill bacteria and germs in swimming pools and drinking water. A little bit of chlorine makes water safe for swimming and drinking by destroying harmful microorganisms.