Element X forms Xⁿ⁺. Atom X and Xⁿ⁺ ion are similar in

Which of the following represent an element that forms ion with a charge of –2?

Which of the following statements explain(s) why the emission spectrum of hydrogen is a line spectrum?
 I. Hydrogen atom has discrete energy levels
 II.   The transition of electrons will only occur      when  a              certain amount of energy is realease.
 III   Electron in the hydrogen atom is in the ground state.

Line emission spectrum of hydrogen is obtained when :
I   electrons move from a lower energy level to a higher            energy level
II  electrons are supplied with energy and excited
III electrons drop from a higher energy level to a lower              energy level

Of the following statements, which is(are) TRUE about atomic structure?
I  Electrons circulate around nuclues in certain orbits. 
II All atoms are made up of protons, neutrons and                     electrons only.
III Almost all the atomic mass is contributed     by the                atomic nucleus.

Information that can be obtained from a study of line spectrum of hydrogen atom includes:
I   Ionisation energy of hydrogen atom
II  the difference in energy between energy levels
III the strength of covalent bond in a hydrogen molecule.

Which of the following statements is (are) TRUE? 
I    Each p-orbital accomodates 6 electron
II   Electrons are assigned to orbitals accoding    to their             energy levels 
III Every higher energy level consists of one       s- orbital            and three p-orbitals.

An atom which has eight electrons in the 3d-orbitals can be arranged based on
 I    Aufbau principle
 II   Pauli exclusion principle 
 III  Hund’s rule

The nucleon number of element T is 31 and its proton number is 15. Of the following statements, which is(are) TRUE about element T?
  I There are five electrons in its valence shell.
  II  It forms a stable ion of T $T^{\ 3-}$  
  III There are three electrons in all orbitals with l=1

What are the possible values of the magnetic quantum number m for an atom with quantum numbers n=5 and l=4?
  I     5 
  II    1, 2, 3, 4,
  III   -4, -3, -2, -1, 0

Which of the following statement(s) about 4f-orbital is(are) TRUE?
I  The principal quantum number is 4 and the azimuthal            quantum number is 3.  
II  The magnetic quantum numbers are -3, -2, -1, 0, 1, 2 and      3.
III A maximum of 14 electrons can be filled in the orbital   

Which of the following electronic configurations exhibit(s) the excited state? 
I     N : 1s2 2s2 2p2 3s1
II    P :  1s2 2s2 2p6 3s2 3p2 3d1
III   K : 1s2 2s2 2p6 3s2 3p6 4s1  

The energy of the electron in a hydrogen atom is determined by
 I  the principal quantum number
II  the magnetic quantum number         
III the electron spin quantum number

Which of the following is the electronic configuration of atom  $_{24}^{52}Y$  ?