Problem 2E

Summarize the history of the atomic idea. How was Dalton able to convince others to accept an idea that had been controversial for 2000 years?

Solution : (a) Calculation of the percent abundance of each element : Given, 293 red spheres are Nv. Blue spheres are 295Nv. There are 12 out of 20 red spheres i.e 293Nv. There are 8 out of 20 red spheres i.e 295Nv. We calculate the percentage abundance of each element as : 293 Percentage abundance of Red colored spheres- Nv : = 60 % Percentage abundance of BLue colored spheres- 295Nv : = 40 % (b) Atomic weight of Nv : Given, mass of 293Nv = 293.15 amu . 295 mass of Nv = 295.15 amu. Atomic weight = percentage abundance(in decimal) Ă—Atomic mass of element 293 As per calculation done above, percentage abundance of Nv = 60% = 0.60 (in decimal). percentage abundance of 295Nv = 40% = 0 .40 (in decimal). Therefore, Atomic weight of Nv = Atomic weight of 293Nv + Atomic weight of 295Nv = (0.60)(293.15amu) + (0.40)(295.15amu) = 175.89 + 118.06 = 293.95 amu. Therefore, Atomic weight of Nv is 239.95 amu