As of 2010, there are 118 known elements. of those, how many are believed to be essential to human biology?

From the 118 known elements, 25 elements are believed to be essential to human biology.

Out of 25 elements , 6 elements namely  – carbon, oxygen, hydrogen, nitrogen, calcium and phosphorus , they make up about 99% of the human body. Some other elements like - potassium, sulfur, sodium, chlorine, and magnesium, they are also found in the human biology.

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