Final answer:
A solution is considered acidic if the concentration of hydronium ions ([H3O+]) is greater than 1 × 10-7 M. In this case, the solution is acidic.
Step-by-step explanation:
A solution is considered acidic if the concentration of hydronium ions ([H3O+]) is greater than 1 × 10-7 M.
On the other hand, a solution is considered basic if the concentration of hydronium ions is less than 1 × 10-7 M.
In this case, since the [H3O+] is 1000 times greater than the [OH-], the solution is acidic.