<Tr> <Td> Hydrogen </Td> <Td_colspan="30"> </Td> <Td> Helium </Td> </Tr> <Tr> <Td> Lithium </Td> <Td> Beryllium </Td> <Td_colspan="24"> </Td> <Td> Boron </Td> <Td> Carbon </Td> <Td> Nitrogen </Td> <Td> Oxygen </Td> <Td> Fluorine </Td> <Td> Neon </Td> </Tr> <Tr> <Td> Sodium </Td> <Td> Magnesium </Td> <Td_colspan="24"> </Td> <Td> Aluminium </Td> <Td> Silicon </Td> <Td> Phosphorus </Td> <Td> Sulfur </Td> <Td> Chlorine </Td> <Td> Argon </Td> </Tr> <Tr> <Td> Potassium </Td> <Td> Calcium </Td> <Td> Scandium </Td> <Td_colspan="14"> </Td> <Td> Titanium </Td> <Td> Vanadium </Td> <Td> Chromium </Td> <Td> Manganese </Td> <Td> Iron </Td> <Td> Cobalt </Td> <Td> Nickel </Td> <Td> Copper </Td> <Td> Zinc </Td> <Td> Gallium </Td> <Td> Germanium </Td> <Td> Arsenic </Td> <Td> Selenium </Td> <Td> Bromine </Td> <Td> Krypton </Td> </Tr>

All of the atoms of argon have the same