To determine \( x + y \), where \( x \) represents the number of electrons in niobium's (Nb) 4d orbitals and \( y \) represents the number of electrons in ruthenium's (Ru) 4d orbitals, we examine their electron configurations:
The sum is calculated as:
\( x + y = 4 + 7 = 11 \)
The sum of 11 is within the expected range of \([11, 11]\), validating the result.
The value of \( x + y \) is 11.
Energy of first Balmer line of H-atom is \( x \) kJ. The energy of the second Balmer line of H-atom is _____