Question

UITGUIC Potassium has three naturally occurring isotopes. They are "K (93.26%, ? amu), "K (0.0117%, 39.964 amu), and 4K (6.73%, 40.962 amu) Calculate the atomic mass of the potassium-39 isotope given that the weighted average of the isotopes is 39.099 amu and using the percent abundances of all the isotopes and the atomic masses of potassium- 40 and potassium-41. Express the mass to three decimal places and include the appropriate units. Submit Request Answer

Answer 1

Atomic mass of potassium - 39 = 38.964 amu

Average atomic - (mass of isotope Ax.l. abundance) +(mass of isotope By 1. abundance) +(mass of isotope cxt. abundance) mass mass mass 1. 39 3k ? 93.26%. 40K 39.964amu 0.0117. 41 k 40.962 am 6.73.1- We have average atomic mass of k=39.099 amu let the mass of 33k ben 33.099 = (x x 93.26) + (39.964 x 0.017) +(40.962 x 6.73) x = 38.964 So the atomic mass of potassium 39 isotope is 38.964 amu.