Question

(i) Calculate the number of electrons which will together weigh one gram .
(ii) Calculate the mass and charge on one mole of electrons .

Answer 1

mass of one electron `= 9.10939 xx 10 ^(-31) kg `
number of electrons that weigh ` 9.10939 xx 10^(-31) kg = 1`
number of electrons that will weigh ` 1 g = ( 1xx 10^(-3) kg) `
`1/( 9.10939xx10 ^(-31)) xx(1xx 10^(-3)kg)`
`0.1098xx 10^(-3) + 31 `
` 0.1098 xx 10^(28)`
`1.098 xx 10^(27)`
(ii) mass of one electron =`9.10939 xx10^(-31) kg`
mass of one electron = `(6.022 xx 10^(23)) xx ( 9. 10939xx 10^(-31) kg)` ltbr gt `5.48 xx 10^(-7) kg`
charge on one electron `= 1.6022 xx 10^(-19) ` coulomb
charge on one mole of electron `= ( 1.6022 xx 10 (-19) C) (6.022 xx10^(23)) `