Final answer:
The statement in question is false; for a substance with a pH of 8, the pOH must be 6, and the substance is considered basic because it has a pH greater than 7.
Step-by-step explanation:
The statement "A substance that has a pH of 8 also has a pOH of 8 and is considered basic." is false. In aqueous solutions at 25°C (standard laboratory conditions), the relationship between pH and pOH is given by the formula pH + pOH = 14.
Therefore, if a substance has a pH of 8, its pOH would be 14 - 8 = 6. According to the pH scale, a substance is considered basic if it has a pH greater than 7, which in this case, it does. Thus, the substance is basic because its pH is 8, but it's not true that its pOH would also be 8.