What enabled moseley to determine the number of electrons in atoms of particular elements?
a. he measured the mass of a given volume of the element
b. he measured the temperature of the element in an ice bath
c. he measured the different wavelengths emitted by the electrons of the element using x-rays
d. he measured the voltage passing through an element connected to a circuit

C. he measured the different wavelengths emitted by the electrons of the element using x-rays

  the volume of  0.220 m k2s    solution  required  to  completely  react with 175 ml  of 0.115m co(no3)2  calculate the moles  of co(no3)2 =  molarity x volume/1000175 x0.115/1000= 0.02  moleswrite  the reacting  equationk2s(aq)  +  co(no3)2  = 2 kno3(aq)  + cos(s)by  use  of mole ratio between k2s to co(no3)2 which  is  1: 1 the moles of k2s is therefore = 175  x0.115/1000= 0.02  molesvolume = moles/molarity=0.02/0.22=0.09  ml  of k2s