Question

Se dau elementele A, B si C. Stiind ca intre numerele lor atomice exista relatiile: ZA+ZB+ZC=20; ZA-ZB=ZC+2; ZA+ZB-ZC=4. Sa se identifice cele trei elemente si sa se reprezinte structurile invelisurilor electronice. help pls:)

Answer 1

ZA+ZB+ZC=20
ZA-ZB=ZC+2
ZA+ZB-ZC=4=>ZA+ZB=4+ZC
4+ZC+ZC=20
4+2ZC=20
2ZC=20-4
ZC=16/2
ZC=8 =>O(oxigen)
ZA-ZB=ZC+2=>ZA-ZB=8+2=> ZA=10+ZB
10+ZB+ZB+8=20
2ZB+18=20
2ZB=20-18
ZB=2/2
ZB=1 =>H (hidrogen)
ZA=10+ZB
ZA=10+1
ZA=11=>Na (sodiu)