How many significant figures should the result have 2.524 g (5.1 • 106 g)

Two

Step-by-step explanation:

In multiplication problems, your answer can have no more significant figures than the number with the fewest significant figures.

Start with the calculation inside parentheses:

5.1 * 10.6 = 54.060 000 00 (by my calculator)

There are three significant figures in 10.6, but only two in 5.1.

In this were a number you had to report, you would round to two significant figures and report the answer as 54.

54.060 000 00 → 54 (to two significant figures)

However, you must multiply this intermediate answer by 2.524.

Therefore, you multiply the number in the calculator by 2.524 and get

54.060 000 00 * 2.524 = 136.447 4400

NOW, you round to two significant figures and report the answer as 140.