Question

You've just solved a problem and the answer is the mass of an electron, me=9.11×10−31kilograms. How would you enter this number into the answer box? Enter your answer in kilograms using three significant figures. Note that the units are provided for you to the right of the answer box.

Answer 1

Answer: $9.11\times 10^{-31}kg$

Explanation:

Significant figures : The figures in a number which express the value or the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

Rules for significant figures:

Digits from 1 to 9 are always significant and have infinite number of significant figures.

All non-zero numbers are always significant.

All zero’s between integers are always significant.

All zero’s after the decimal point are always significant.

All zero’s preceding the first integers are never significant.

Thus $9.11\times 10^{-31}kg$ has three significant figures