The moon ariel orbits uranus at a
distance of 1.91 x 10^8 m once every
2.52 days. use that data to calculate
the mass of uranus.
[? ] x 10^[? ]kg

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.

e/c, where e is its total energy