Question

Question

The mass of a dust particle is approximately 7.5×10^−10
kilograms and the mass of an electron is 9.1×10^−31
kilograms. How many electrons does it take to equal the mass of a dust particle?(1 point)
Responses

6.8×10^−41

8.2×10^−20

1.2×10^−21

6.8×10^−40

8.2×10^20

1.2×10^21

Answer 1

To find the number of electrons that equal the mass of a dust particle, we need to divide the mass of the dust particle by the mass of an electron:

(7.5×10^−10 kg) / (9.1×10^−31 kg) = (7.5 / 9.1) × 10^(−10+31) = 0.8241 × 10^21 = 8.24 × 10^20

Therefore, it takes approximately 8.24 × 10^20 electrons to equal the mass of a dust particle.

Among the given options, the closest answer is 8.2×10^20.