Periodic chart .....................?

Question

Are the elements at the beginning of the chart more common than the end of the chart?

does that mean that oxygen is the 8th most common element in the universe?

Answer 1

No, in fact oxygen is the 3rd most common element in the universe. The number you see in the upper corner of the chart is the element's atomic number. This number is derived from it's number of electrons, protons and neutrons. If you know the formula in getting this, then you'd understand how they're related. I suggest you read more or search more.

Answer 2

No that is not the way it works.

The abundance of a chemical element measures how relatively common the element is, or how much of the element there is by comparison to all other elements. Abundance may be variously measured by the mass-fraction (the same as weight fraction), or mole-fraction (fraction of atoms, or sometimes fraction of molecules, in gases), or by volume fraction. Measurement by volume-fraction is a common abundance measure in mixed gases such as atmospheres, which is close to molecular mole-fraction for ideal gas mixtures (i.e., gas mixtures at relatively low densities and pressures).

For example, the mass-fraction abundance of oxygen in water is about 89%, because that is the fraction of water's mass which is oxygen. However, the mole-fraction abundance of oxygen in water is only 33% because only 1 atom in 3 in water is an oxygen atom. In the universe as a whole, and in the atmospheres of gas-giant planets such as Jupiter, the mass-fraction abundances of hydrogen and helium are about 74% and 23-25% respectively, while the (atomic) mole-fractions of these elements are closer to 92% and 8%. However, since hydrogen is diatomic while helium is not in the conditions of Jupiter's outer atmosphere, the molecular mole-fraction (fraction of total gas molecules, or fraction of atmosphere by volume) of hydrogen in the outer atmosphere of Jupiter is about 86%, and for helium, 13%.

Hydrogen is the most abundant element in the known Universe; helium is second. However, after this, the rank of abundance does not continue to correspond to the atomic number; oxygen has abundance rank 3, but atomic number 8. All others are substantially less common.

Element - Parts per million

Hydrogen - 739,000

Helium - 240,000

Oxygen - 10,700

Carbon - 4,600

Neon - 1,340

Iron - 1,090

Nitrogen - 950

Silicon - 650

Magnesium - 580

Sulfur - 440

All Others - 650