Final answer:
To express 0.030498 in 3 significant figures, we account for the first three non-leading zeros which are '3', '0', and '4', resulting in 0.0304. The fourth digit '4' does not cause the third significant figure to round up.
Step-by-step explanation:
To express 0.030498 in 3 significant figures, we start by identifying the first non-zero digit as the first significant figure. In this case, the '3' is the first significant figure. The next two digits after the '3' are '0' and '4', these will be the second and third significant figures. Now we have the first three digits '0.030' but we need to look at the fourth digit to determine whether we should round up. Since the fourth digit is '4', which is less than 5, we do not round up the third significant figure. Thus, we keep the '0.030' as it is without rounding.
However, when expressing significant figures, trailing zeros right after the decimal sign may or may not be considered significant based on the context. Since we only care for three significant figures, we can remove the trailing zeros that are not significant. The answer, in this case, to the required number of significant figures, will be 0.0304, matching option 2).