5.3 a₀ (Bohr radius) is equal to 0.0000000009201572899175521 ft (foot). To convert from Bohr radius to foot, multiply by 0.00000000017361458300331172 or divide by 5,759,884,813.252841.
physical constant; the most probable distance between an electron and the nucleus in a nonrelativistic model of the hydrogen atom with infinitely heavy nucleus