Question

how would you round off your final answer using significant figures? isotope abundance relative mass mass contribution ga-69 0.601089 68.925580 amu 41.430408 amu ga-71 0.398929 70.924701 amu 28.293920 amu 69.724328 amu 69.7243 amu isotope abundance relative mass mass contribution ga-69 0.601089 68.925580 amu 41.430408 amu ga-71 0.398929 70.924701 amu 28.293920 amu 69.724328 amu 69.72433 amu

Explanation:

Step1: Recall significant - figure rules

When rounding, look at the digit to the right of the last significant digit you want to keep.

Step2: Identify the number to round

We have 69.724328 amu. If we want to round to five significant figures.

Step3: Apply the rounding rule

The digit in the sixth place is 2. Since 2 < 5, we drop it. So 69.724328 rounds to 69.724 amu. But if we assume we want to round to six significant figures, the digit in the seventh place is 8. Since 8 > 5, we round up the previous digit. So 69.724328 rounds to 69.7243 amu.

Answer:

69.7243 amu