What chemical elements are considered primary elements?
Typically the question of primary elements comes from biology and usually from the aspects of genetics.
Therefore the primary elements would carbon, hydrogen, oxygen, nitrogen and phosphorus. These are the primary elements bound in cells, DNA and RNA. The three main organic molecules are composed of Carbohydrates CHO, Fats CHO and Proteins CHON.
However, there are many essential elements necessary in small amounts, like sulfur, potassium, iron and magnesium.
I hope this was helpful.