The electron cloud has such a small mass because that's where all the electrons are! Electrons are fundamental particles having a mass of only 9.109 X 10-31 kg. To put that into perspective, a proton has a mass of over 1,800 times that of the electron.
Chat with our AI personalities
Any number that is very large, or very small (near zero). For example, the mass of the Sun in kilograms (large), the distance to the M31 galaxy in meters (large), or the mass of the electron in kilograms (small).
One kWh has 2.25 x 1025 eV. (The electron-volt is a very small unit, used in particle physics.)
Its mass remains the same (except for the very small amounts that stick to the knife blade).
Not in the theoretical world, in the practical world: just a very little. The period is determined primarily by the length of the pendulum. If the rod is not a very small fraction of the mass of the bob then the mass center of the rod will have to be taken into account when calculating the "length" of the pendulum.
The formula E=mc2 states that the conversion ratio of mass to energy is "Energy=mass times the speed of light squared" (which indicates that the conversion of a small amount of mass can create a very large amount of energy).