the mass of a helium-4 atom is 6, point, 6, 5, times, 10, to the power minus 246.65×10 −24 grams. the mass of an electron is 9, point, 1, 1, times, 10, to the power minus 289.11×10 −28 grams. how many times greater is the mass of a helium-4 atom than the mass of an electron? write your answer in standard notation, rounding to the nearest tenth.

1 answer

To compare the masses of a helium-4 atom and an electron, we first need to express both masses in scientific notation correctly and then divide them.

  1. Mass of Helium-4 Atom:

    • Given: \( 6.65 \times 10^{-24} \) grams
  2. Mass of Electron:

    • Given: \( 9.11 \times 10^{-28} \) grams

Now, to find out how many times greater the mass of the helium-4 atom is than the mass of the electron, we can set up the following division:

\[ \text{Ratio} = \frac{\text{Mass of Helium-4}}{\text{Mass of Electron}} = \frac{6.65 \times 10^{-24}}{9.11 \times 10^{-28}} \]

To simplify the calculation, we can divide the coefficients and subtract the exponents:

  1. Divide the coefficients: \[ \frac{6.65}{9.11} \approx 0.729 \]

  2. Subtract the exponents (when dividing exponents in scientific notation): \[ -24 - (-28) = -24 + 28 = 4 \]

So now we can express the result: \[ \text{Ratio} \approx 0.729 \times 10^{4} \]

Convert this into standard notation: \[ 0.729 \times 10^{4} = 7290 \]

Finally, rounding to the nearest tenth, we have: \[ \boxed{7290.0} \]

Thus, the mass of a helium-4 atom is approximately 7290.0 times greater than the mass of an electron.