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! read more

Atoms in the Body On average, 87% of the atoms in the body are hydrogen or oxygen. Carbon, hydrogen, nitrogen, and oxygen together account for 99% of the atoms in a person. read more

In summary, for a typical human of 70 kg, there are almost 7*10 27 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. read more

Ninety-nine percent of the atoms in the human body can be divided into the following amounts: 65 percent hydrogen, 24 percent oxygen and 10 percent carbon. read more

Be sure to keep in mind that the following numbers are based on the number of atoms, not percent of body weight (by weight we are mostly oxygen). A 70 kg body would have approximately 7*10 27 atoms. That is, 7 followed by 27 zeros: 7,000,000,000,000,000,000,000,000,000. Of that, 4.7*10 27 would be hydrogen atoms, which have one proton and one electron each. read more