Any of a group of rare gases are Noble Gases , lets look at a few examples : helium, neon, argon, krypton, xenon

Helium Has 2 proton , 2 electrons and 2 neutrons , thus it has a atomic number for 2

Its symbol presents H and its relative mass ( mass of all the isotopes of the element and the element itself divided by number of isotopes and the element )

Its electron structure - 2 , only 2 electrons at first shell

Its melting down temperature is -270 and its boiling down temperature is -269

Neon has 10 protons, 10 neutrons and 10 electrons , which has an atomic number of 10 protons

Neon symbolizes as Ne and its relative mass is 20.1797

The electron arrangement for Neon is 2,8

Neon melts at -249 and boils at -246

Argon has 18 protons , 18 neutrons and 18 electrons , it has an atomic number of 18

Argon symbolizes as Ar and has a relative mass of 39.948

Argon electron structure - 2,8,8,

It melts at -189 and boils at -186