Nitrogen or if your talking about the crust Silicon
Oxygen is the most common element in the crust.
coal
The second most common element on Earth is silicon, which makes up about 28% of Earth's crust. The most common element found on a Earth is oxygen which is about 47%.
Ca is the symbol for calcium, which is the most common element found in bones. Phosphorus is also important for bone health.
Nitrogen.
Oxygen is the most common element in the crust.
Nitrogen is the most common element found in Earth's atmosphere, making up about 78% of the air we breathe. Oxygen is the next most abundant element in Earth's atmosphere, making up about 21%.
Selenium is not a common element but is necessary.
OXYGEN
Silicon.
If you mean the most common element it is hydrogen.
The most common element found in all living things is not, as you would think, oxygen. It is carbon an can be found in every living organism. That is why organic material gives of Carbon and Oxygen as it rots or burns.