Yep, the smallest atom, hydrogen, weights ~ 6 * 10^-23 of a gram [1] (that's 0.000... some 23 zeroes ... and corresponds to 1 "atomic unit"), and other atoms we

Yep, the smallest atom, hydrogen, weights ~ 6 * 10^-23 of a gram [1] (that's 0.000... some 23 zeroes ... and corresponds to 1 "atomic unit"), and other atoms weight just tens or hundreds times more (so still in same ballpark). The bases (the letters in the four letter DNA alphabet), mostly built up of light atoms, weigh each just a bit over 100 of such tiny parts of a gram (atomic units, or g/mol, to be exact) [2] [3] [4] [5]. They appear in pairs, but still, even given that a pair weighs around 300 * 6 * 10^-23 g, you can fit quite a few of such base pairs in a few grams. Ca 3.3×10^20 / g, or ~ 330 000 000 000 000 000 000, given this rough esti-calculation. [1] https://en.wikipedia.org/wiki/Mole_(unit)#Definition_and_related_concepts https://en.wikipedia.org/wiki/Mole_(unit)#Definition_and_rel... [2] A: https://en.wikipedia.org/wiki/Adenine https://en.wikipedia.org/wiki/Adenine [3] C: https://en.wikipedia.org/wiki/Cytosine https://en.wikipedia.org/wiki/Cytosine [4] G: https://en.wikipedia.org/wiki/Guanine https://en.wikipedia.org/wiki/Guanine [5] T: https://en.wikipedia.org/wiki/Thymine https://en.wikipedia.org/wiki/Thymine