Quais são as substâncias puras, simples e quais são compostas?
a) HCI _________
b) H² __________
c) O³ __________
d) mg (OH)² _________
e) CaCO³ ___________
f) He ________
g) KI __________
h) H²CO³ ______
i) CO² _________
j) N² __________