what element is the most abundant on the earths crust
Abundance of the chemical elements The mass-abundance of the nine most abundant elements in the Earth's crust is approximately: oxygen 46%, silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium 2.0%, and titanium 0.61%. Other elements occur at less than 0.15%. For a complete list, see abundance of elements in Earth's crust.
Chemical element A chemical element is a species of atoms having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).[1] 118 elements are identified, of which the first 98 occur naturally on Earth with the remaining 20 being synthetic elements. There are 80 elements that have at least one stable isotope and 38 that have exclusively radionuclides, which decay over time into other elements. Iron is the most abundant element (by mass) making up Earth, while oxygen is the most common element in the Earth's crust.[2]