Helium is a chemical ELEMENT of the family of noble gases. Its chemical symbol is 'He' which has an atomic number of 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table. Although it doesn't really react under normal conditions, it is the second most abundant element in the universe.
Elements are pure substances that cannot be broken down any further.