Question

Consider the elements of actinoid series from Actinum (Ac) to Lawrencium (Lr), if the number of elements having only oxidation state +3 is x, and elements having +6 oxidaiton state is y, calculate value of 10xy

Answer 1

120

Answer 2

The actinoid series comprises 15 elements from Actinium (Ac, Z=89) to Lawrencium (Lr, Z=103).

1. Elements with only +3 oxidation state (x):

   • Actinium (Ac): Exhibits only +3.
   • Fermium (Fm): Primarily +3, other states are very unstable. Considered only +3 for competitive exams.
   • Lawrencium (Lr): Exhibits only +3. Thus, $x = 3$.

2. Elements with +6 oxidation state (y): The elements that exhibit a +6 oxidation state are:

   • Uranium (U)
   • Neptunium (Np)
   • Plutonium (Pu)
   • Americium (Am) Thus, $y = 4$.

3. Calculate 10xy: $10xy = 10 \times 3 \times 4 = 120$.