Answer:
0.265 grams Be (3 sig. figs. per coefficient of given 1.77 x 10²² atoms Be)
Explanation:
Calculation Sequence: #atoms => #moles by dividing by Avogadro's Number (6.02 x10²³) => #grams (multiply #moles by Be formula weight - 9.012g/mol
Given 1.77 x 10²² atoms Be = 1.77 x 10²² atoms Be x 1 mole Be/6.02 x 10²³ atoms Be/mole Be x 9.012 g Be/mole Be = 0.26497 (calculator answer)
= 0.265 grams Be (3 sig. figs. per coefficient of given 1.77 x 10²² atoms Be)
