Question

the charge on a electron is 4.8*10^-10 esu what is the value charge of in li+1 ion

Answer 1

There are two ways of defining what 1 Coulomb of charge is. Both use correct equations. The old one is based on the very definition of charge, but the second one is always used now, because its gives a better accuracy.Using the formula, F = q x E , where F (in Newtons, N) is the electrostatic force on a small test charge q (in Coulombs, C)in an electric field E (in Volts per metre, V/m), we can say that 1 C is that charge on an object, that gives an electrostatic force of 1 N, when placed in an electric field of 1 V/m.The new formula that is used, is,Q = I x t, where Q is the charge that passes a point in a circuit in a time t (in seconds), when the current in the circuit is I ( I is the standard symbol of current, measured in Amps, A). So 1 C is the charge that passes a point in a circuit in 1s, when the current through the circuit is 1 A.1 A is a low and pretty typical current, for household electrical appliances. These currents typically flow through copper wires, and are carried by the free electrons in the metal. Now, since we know that the charge on one electron is 1.6 x 10^-19 C, we can calculate how many electrons pass one point in the circuit, in 1 second, for a current of 1 A, N say.N = 1/1.6x10^-19 = 0.625 x 10^19= 6.25 x 10^18 electrons. This is a HUGE number. Imagine that each electron was a fine grain of sand of diameter 0.1 mm, and we used all of these sand grains to make a cube of sand. You should be able to verify that this cube would be about 100m high!There have been many experiments done to measure the charge on an electron. Some are chemical, some are physical, but, they are all ingenious. The simplest one’s to perform are electrolysis experiments, but they do rely on quite a lot of chemical theory. My favourite is the one first done by Millikan, known as the oil drop experiment. This is a physical experiment, using the first of the formulas above, which did give an excellent value for the charge on an electron. It's too detailed to explain here. Just Google ‘oil drop experiment’