(a) What equal positive charges (in Coulombs) would have to be placed on two celestial objects with masses 9.40 x 1027 and 1.99 x 1022 kg to neutralize their gravitational attraction? (b) What mass of hydrogen would be needed to provide the positive charge calculated in (a)?
I was able to get the first part right. My answer was 1.18 x 10^15 C.
For b, using q = ne, do I just have to divide it by the constant e?
It won't accept my answer though.
If you have Q correct, then you should be able to use
Q = n e for the number of hydrogen atoms (protons) needed, n. You would have to divide that by Avogadro's number, or multiply it by the mass of a proton, to get the mass of all the protons.
hydrogen mass (g) = (number of hydrogen nuclei)(1 gm/mole)/(# of atoms/mole)
Do the following calculations, and write the answers with the correct number of significant figures.
(a) 15.45 m 8.21 m
To calculate the mass of hydrogen needed to provide the positive charge calculated in part (a), you need to use Avogadro's number and the molar mass of hydrogen.
First, let's find the number of electrons needed to obtain the positive charge of 1.18 x 10^15 C. We know that the elementary charge, e, is approximately 1.6 x 10^-19 C. Therefore, the number of electrons required can be calculated as:
Number of electrons = Charge / elementary charge = (1.18 x 10^15 C) / (1.6 x 10^-19 C)
Performing the calculation, we find that the number of electrons needed is approximately 7.375 x 10^33.
Since hydrogen has one electron per atom, the number of hydrogen atoms needed will be the same as the number of electrons. Therefore, we have:
Number of hydrogen atoms = Number of electrons = 7.375 x 10^33
Now, we need to convert the number of hydrogen atoms to mass using Avogadro's number (6.022 x 10^23 atoms/mole) and the molar mass of hydrogen (approximately 1.008 g/mole).
Mass of hydrogen = (Number of hydrogen atoms) / Avogadro's number * Molar mass of hydrogen
Performing the calculation:
Mass of hydrogen = (7.375 x 10^33 atoms) / (6.022 x 10^23 atoms/mole) * (1.008 g/mole)
This yields a mass of hydrogen of approximately 120.8 g.
Therefore, the mass of hydrogen needed to provide the positive charge in part (a) is approximately 120.8 grams.