Which orbital in each of the following pairs is lower in energy in a many electron atom? 4d,5f

Which number in each of the following pairs is to the right of the other on the number line? 4,9

Which number in each of the following pairs is to the right of the other on the number line?< 0,-5

In which of the following pairs, the atomic size is almost the same ?

which of the following subshell can accommodate as many as 10 electrons?

Because of lanthanoid contraction, which of the following pairs of elements have nearly same atomic radii? (Numbers in the parenthesis are atomic numbers)

Which of the following pairs have almost similar atomic radii ?

Which of the following pairs of elements would have a more negative electron gain enthalpy? i) O or N ii) F or Cl

Which of the following contains maximum number of lone pairs of electrons on the central atom ?