A free radical is an atom or molecule that has an unpaired electron, making it highly reactive. These unstable particles can cause damage to cells, proteins, and DNA by stealing electrons from other molecules, leading to a chain reaction of instability. Free radicals are produced naturally in the body during processes like metabolism, but they can also come from external sources such as pollution, radiation, and cigarette smoke. Antioxidants are substances that can neutralize free radicals by donating an electron, thus preventing cellular damage. Foods rich in vitamins C and E, such as fruits and nuts, are known to provide antioxidants. Maintaining a balance between free radicals and antioxidants is essential for overall health and can help reduce the risk of various diseases.