Please help me! very urgent!
chemical elements are given and their valence is indicated. make up the appropriate chemical formulas:
1 2 5 6 3 7 3 2 5 3 1
Li O Ba O P O Sn O P H Mn O Fe O H S N O Cr Cl Ca Cl
3 2 3 1 3
Mg N Al S Fe Cl Si Cl Ca P
1 4 4 4
Si O Al Cl N O Al O Si H Mg Si