What element is commonly added to treat potable water to kill microbes?

Chlorine is commonly added to potable water as a disinfectant to kill harmful microbes that can cause diseases. This process, known as chlorination, has been widely adopted in water treatment facilities because chlorine is effective at eliminating bacteria, viruses, and other pathogens present in the water supply.

When chlorine is added to water, it forms various compounds that can penetrate microbial cell walls, leading to cell destruction and ensuring that the water is safe for human consumption. The residual chlorine that remains after treatment continues to help protect the water as it moves through pipes to homes and businesses.

Other options do not serve this specific purpose. For example, hydrogen is a reactive gas and not used for disinfection; fluorine, while sometimes added to drinking water for dental health, does not act as a disinfectant; and helium is an inert gas without antimicrobial properties. This makes chlorine the preferred choice for ensuring water safety through microbial disinfection.