Name, Argon. Symbol, Ar. Atomic Number, 18. Atomic Mass, 39.948 atomic mass units. Number of Protons, 18. Number of Neutrons, 22. Number of Electrons, 18. Melting Point, -189.3° C. Boiling Point, -186.0° C. Density, 1.784 grams per cubic centimeter. Normal Phase, Gas. Family, Noble Gases. Period, 3. read more
Argon’s atomic no. is 18. Hence it contains 18 electrons. Since atomic number is equal to no. of protons present in an atom. And no. of protons equals to the number of electrons present in an atom. read more
Argon has 18 protons and 18 electrons. Its atomic number is 18, and its mass number is 40 grams per mole. Argon is a noble gas and is found in group 18 on the periodic table. read more