Every element has an atomic number. The atomic number value also represents the number of protons and electrons that are found in the element. Argon has an atomic number of 18, which means it has 18 protons and 18 electrons. The element symbol for argon is Ar.
Argon is a colorless gas that was discovered in 1894 by Sir William Ramsay. The name originates from the Greek word argon, which means inactive. Argon is in the noble gas group of elements.Learn more about Atoms & Molecules