|Atomic Number:|| 2|
|Atomic Mass:|| 4.0026 amu|
Helium is gas element. It is lighter than air, so it rises to the means of it being possible. It's atomic number is 2, And atomic wheight is 4.00. It is the second most abundant element in the universe and was discovered in 1895 by Sir William Ramsay. Helium is so light that helium atoms float up, out of the atmosphere because the Earths gravity cannot pull it in. Radioactive deacay creates helium. Helium can be used in many way, but in balloons is the most well known. It can also be used in fuels like rocket fuels and air craft fuels.