how many atoms in the human body
In summary, for a typical human of 70 kg, there are almost 7*1027 atoms (that's a 7 followed by 27 zeros!) Another way of saying this is seven billion billion billion.. Of this, almost 2/3 is hydrogen, 1/4 is oxygen, and about 1/10 is carbon. These three atoms add up to 99% of the total!