Explanation:

Helium

• It is a chemical element with the symbol He and atomic number 2. The British chemist Sir William Ramsay discovered the existence of helium on Earth in 1895.
• It is a colourless, odourless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table.
• Its boiling point is the lowest among all the elements.

Electrons

• Matter is made up of atoms, which are the basic units of chemical elements such as hydrogen, helium or oxygen.
• Atoms are made up of three particles: Protons, Neutrons and Electrons.
• Hence, electrons are the subatomic particles that orbit the nucleus of an atom. They are generally negative in charge and are much smaller than the nucleus of the atom.

Hence all statements are correct.