Answer:
O2
Explanation:
At standard temperature and pressure, oxygen is found as a gas consisting of two oxygen atoms, chemical formula O2.
The answer is chemical weathering .
Answer:
O a 2 in front of hydrochloric acid
Explanation:
the given reaction is :-
=》Zn + 2 HCL -> ZnCl2 + H2
since, mass can't be created or destroy, so number of hydrogen atoms in the reaction should be equal in product as in reaction.
so, there is 2 hydrogen in product hence there are two hydrogen in the reactants also.
it is showed in the reaction by putting a 2 in front of hydrochloric acid ( HCl ).