The mass of a dust particle is approximately 7.5×10−10

Question

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

8.2×10−20
8 point 2 times 10 to the negative 20 power

1.2×10−21
1 point 2 times 10 to the negative 21 power

6.8×10−41
6 point 8 times 10 to the negative 41 power

1.2×1021
1 point 2 times 10 to the 21th power

6.8×10−40
6 point 8 times 10 to the negative 40 power

8.2×1020

Answer 1

To find out how many electrons are needed to equal the mass of a dust particle, you would divide the mass of the dust particle by the mass of an electron.

1. Mass of the dust particle: \(7.5 \times 10^{-10}\) kg
2. Mass of an electron: \(9.1 \times 10^{-31}\) kg

Now divide the mass of the dust particle by the mass of an electron:

\[ \text{Number of electrons} = \frac{\text{Mass of dust particle}}{\text{Mass of an electron}} = \frac{7.5 \times 10^{-10}}{9.1 \times 10^{-31}} \]

Calculating this:

\[ \frac{7.5 \times 10^{-10}}{9.1 \times 10^{-31}} \approx 8.24 \times 10^{20} \]

When rounded, this value is approximately \(8.2 \times 10^{20}\).

Thus, the answer is:

8.2×10²⁰