how many atoms are there in an ounce of gold?

Question

I'm trying to find out how much 1 atom of gold is worth at todays market price.

Answer 1

Here is how to do this:

By definition, a mole of gold contains 6.02 x 10^23 atoms. A mole of gold weighs 197g. 1 oz is 28.35g if you're using avoirdupois oz , but I think the price of gold is listed in troy oz which are 31.1g (check on this).

So, 1 oz = (31.1/197) x 6.02 x 10^23 atoms.

= 9.50 x 10^22 atoms; so cost per atom is:

Current cost of gold in $/troy oz/9.50 x 10^22atom/troyoz

Answer 2

First, gold is priced in dollars per Troy ounce on the London Metals Exchange. Troy ounces are 31.1g, whereas the Avoirdupois ounces we use to buy pounds and quarts of food are 28.4g. The atomic weight of gold is 197. Let a Troy ounce be called toz.

1tozAu x 31.1gAu/1toz x 1molAu/197gAu x 6.02x10^23atomAu/1molAu = 9.5 x 10^22 atoms Au

I hear that the price of gold is around $700-800/oz (Troy)

Answer 3

1 ounce Au = 28.3495 grams Au
28.3495 grams Au (1 mol Au/ 196.96 grams Au) = 0.1439 mol Au
0.1439 mol Au (6.02*10^23 atoms Au/1 mol Au) = 86,649,060,722,989,439,480,098 atoms Au