Which of the following measurements has three significant figures? a. 1.02 x 10^-3 g b. 0.089 g c. 100 g d. 7.8 x 10^-6 g

Let us calculate the significant figures of each of the given measurements.

We know that the leading zeros are non significant.

Hence, the number of significant figures is 3

Similarly, 0.089 g has 2 significant figures.

100 has 1 significant figure because trailing zeros are non significant.

Finally, has 2 significant figures.

Therefore, has three significant figures.

A is the correct option.