chemistry
posted by john on .
what is the mass in grams?
a) 3.011 x 10^23 atoms F
b)1.50 x 10^23 atoms Mg
c)4.50 x 10^12 atoms Cl
d)8.42 x 10^18 atoms Br
e) 25 atoms w
f) 1 atom Au
can you please explain a and b to me then i'll come back later and see if i did the rest right? Thanks in advance

Use stochiometry
a) Molar mass F = 19g/mol
so...
(3.011 x 10^23 atoms F) X (1molF/(6.022 x10^23atoms)X (19g/1mol F) = 9.5 g F
(1molF/(6.022 x10^23atoms) = Avogardro's Law can be used in any situation such as this. Use it for the rest of the questions listed in the same way shown above. 
but how would the answers by in scientific notations

balls