Question

Determinati numarul de electroni a 6.4 grame de sulf.

Answer 1

Intai facem configuratia electronica a sulfului:
[Ne] 3s2 3p4
n=m/M = 6,4/32=0.2 moli
1 mol   ... 6,022 * 10^23 atomi
0.2 moli... x atomi
x = 0.2 * 6,022 * 10^23
x = 1.2044 * 10^23
1 atom .................. 15 electroni
1.2044 * 10^23 ......  y electroni
y= 15*1.2044*10^23=18.066*10^23

Answer 2

Masa molara a sulfului este de 32 g/mol.
Si stim,ca intr-un mol de substanta se gasesc 6.022*10^23 enitati elementare,in acest caz atomi de sulf.
Dar,sulful are numarul atomic 16,ceea ce inseamna ca sunt in 16 electroni/atom.
Deci in 32g.....16*6,022*10^23 electroni
           6.4g......x electroni

x=(6.4*16*6.022*10^23)/32=19,2704*10^23 electroni
Daca vrei poti face rezultatul sa arate putin mai bine facand asta:
192704*10^-4*10^23=1922704 * 10^19 electroni.