1) I2, CCl4
HBr
Na2S K2O ( COMPUSII IONICI, carea sunt compusii metalelor)
2. Z1= 20--> Ca A,Ca= 40g/mol
Z2= 2+2+6+2+4=16----> S A,S= 32g/mol
1mol................1mol
Ca + S------> CaS
40g....................(40+32)g
80g.......................x.....................................calculeaza !!!!!