Haase,+Paige

Helium (He) ß bohr model.

Boiling point:-268.98 Melting point: 272.2 Atomic number: 2 [|Atomic mass:4.002602] Was discovered by Sir William Ramsey

for many years it was an element that was just on the sun not known to earth yet.

In 1895 is when Sir William Ramsey found it on earth for the first time. Density (kg m-3 ): 120 (4.22 k) It depends on what your buying to see how much it is like ballons have helium and they are about 1$ a pack. The highest price is like 300. for many years it was an element that was just on the sun not known to earth yet.