Question

The mass of an electron is approximately 0.000,000,000,000,000,000,000,000,000,000,911 kilograms. Identify its correct scientific notation.

9.1 x 10^-30 kg
9.1 x 10^30 kg
9-11 x 10^31 kg
9.11 x 10^-31 kg

Answer 1

D. 9.11 x 10^-31 kg

When converting to scientific notation, move the decimal until it reaches a value besides zero.

In this problem, you have to move the decimal until it's after the 9, you have to move it 31 times to do this. and since the number is on the right of the decimal you know that it's a negative value. This makes D the correct answer.