Because despite being natural they still harm the ozone layer and cause breathing problems, even suffocation.
Please show the whole question including the diagram so that you can receive help with the question.
H2O or water, all humans are mostly mad of water and water covers most of the earth
Most atoms have more neutrons than protons which accounts for basically half of the nucleuses mass.
Answer: Atomic Nucleus!
Explanation: All atoms have a dense central core called the atomic nucleus. Forming the nucleus are two kinds of particles: protons, which have a positive electrical charge, and neutrons, which have no charge.
(Yes, it was from google.)
