How do atoms of oxygen and hydrogen differ?

Answer 1

A hydrogen atom is made from one proton and one electron. An oxygen atom has 8 protons and 8 electrons. Hence their "Atomic Numbers" are "1" for hydrogen and "8" for oxygen.

However their "Atomic Weights" are 1 for hydrogen and approximately 16 for oxygen because, in a normal atmosphere, hydrogen exists as a gas cloud of single atoms whereas oxygen exists as a gas cloud consisting of pairs of atoms.

Answer 2

Oxygen's nucleus contains 8 protons vs. Gold's nucleus which contains 79 protons. The number of neutrons in both can vary depending on isotope. Another consequence of Oxygen's lower atomic number results in a solitary atom not having "enough" electrons in its outer shell, so it will readily combine with many other atoms to create molecules with a "full set." This is why Oxygen forms a part of many compounds and is very chemically reactive when it's by itself. So much so, that when Oxygen is by itself, it will "partner up" with another Oxygen atom to share their outer electrons with each other, so you almost always find free oxygen in pairs (O2).