#3**+5 **

By definition one gram-mole of a substance contains (approximately) 6x10^{23} atoms (this is known as Avogadro's number or Avogadro's constant).

The atomic weight of silicon is 28, so Avogadro's number of silicon atoms weigh 28 grams. Therefore 1 atom of silicon weighs (28/Avogardo's number) grams.

Do a search on Avogadro's number to find a more accurate value than I've used here; and search on atomic weight of silicon to find the value of 28.

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Alan
Apr 25, 2015

#1**+5 **

6x10^{23} atoms of silicon weigh 28 grams, so one atom of silicon weighs 28x10-^{23}/6 grams ≈ 4.7x10^{-23} grams

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Alan
Apr 23, 2015

#3**+5 **

Best Answer

By definition one gram-mole of a substance contains (approximately) 6x10^{23} atoms (this is known as Avogadro's number or Avogadro's constant).

The atomic weight of silicon is 28, so Avogadro's number of silicon atoms weigh 28 grams. Therefore 1 atom of silicon weighs (28/Avogardo's number) grams.

Do a search on Avogadro's number to find a more accurate value than I've used here; and search on atomic weight of silicon to find the value of 28.

.

Alan
Apr 25, 2015