-numarul de neutroni din 1 atom se afla din Z si A, deoarece A=protoni+neutroni= Z+ prot
neutroni= 40-20= 20 intr-un atom
m=40g este masa pentru 1 molCa
1molCa are 6,023x10²³ atomi(numarul lui Avogadro)
1 atom...are.....20neutroni
6,023x10²³atomi.........20x6,023x10²³ neutroni=..................calculeaza !!
-Z=9electroni= 9 protoni/ atom
n=5000moli
N,atomi= n,molxN,A ,atom/mol; N=5000tx6,023x10²³= 30,115x10²³ atomi
1atom...................9 electroni
30,115x10²³atomi...........N= ....calculeaza !!!!!!
-F are configuratia 1s2 2s2 2p5