Small Changes, Big Differences
I had an interesting thought. What's the difference between hydrogen and helium? Helium is an inert, more stable, and non-flammable gas. Compared to hydrogen with is less stable, reactive, and extremely flammable. Hydrogen is the most abundant element in the universe, estimated to be about 75 percent of the universe's normal matter. Helium is estimated to be about 25 percent of the atoms in the universe. And that gets me to the real difference. Hydrogen, as the first element on the periodic table, has one proton and one electron. With only one proton, a neutron isn't needed because there isn't a positive to positive repulsion that would occur if there were two protons). However, hydrogen has three isotopes: protium-1H has no neutrons, deuterium-2H with one neutron, and tritium-3H has two neutrons. The difference is helium has two protons and two neutrons, surrounded by two electrons. Since hydrogen isotope can have two neutrons, the key difference between hydrogen and h...