Differences between a weak acid and a dilute acid

What is the result of multiplying (2.5 × 1010) × (2.0 × 10-7)? a. 5.0 × 103 b. 5.0 × 10-3 c. 5.0 × 1017 d. 5.0 × 10-17

How are isotopes of the same chemical element alike? how are they different?

Which of the following are sources of revenue for media companies? a. direct sales to producers b.advertising and subscriptions c. online purchase d. capital investments