Choose the correct statement regarding the energy levels of hydrogen-like atoms:

• the ground state corresponds to the 2s¹ electronic configuration

• the energy of the 2p orbital is higher than that of the 2s orbital

• the energy of the 2s orbital is higher than that of the 2p orbital

• all 3s, 3p, and 3d orbitals have the same energy

Choose the correct statement regarding the radial wavefunction R_(r) in hydrogen-like atoms:

• It is maximum when

  r → 0 for s-type orbitals

• The orbital 2p has 2 radial nodes

• It is maximum when

  r → 0 for p-type orbitals

• The orbital 2p has 1 radial node

Choose the correct statement regarding the angular wavefunction, γ_(θ,φ),of the hydrogen-like atoms:

• The number of angular nodes is n (principal quantum number)

• The orbital 2s has 1 angular node

• The orbital 2p has no angular nodes

• The number of angular nodes is l (angular momentum quantum number)

Which of the following combinations of quantum numbers is not correct?

• n = 1

  l = 0

  m_l = 0

• n = 3

  l = 3

  m_l = 0

• n = 4

  l = 3

  m_l = -1

• n = 2

  l = 0

  m_l = 0

Choose the correct statement regarding the energy of orbitals in multielectronic atoms:

• All orbitals in the same electronic shell have the same energy

• All orbitals in the same electronic sub-shell have the same energy

• Orbitals in 2p sub-shell have lower energy than those in the 2s sub-shell

• Sub-shell 3d has 3 energetically degenerated orbitals

The atomic radius decreases as we move from left to right across a period in the Periodic Table because:

• The atom's electronegativity increases

• The atom's electronegativity decreases

• Inter-electronic repulsion decreases

• The effective nuclear charge (Z_eff) increases

Choose the correct answer regarding the C-O bond order in CO₂ and [CO₃]²⁻

• Both compounds have the same C-O bond order

• The C-O bond order in CO₂ is greater than in [CO₃]²⁻

• The C-O bond order in CO₂ is less than in [CO₃]²⁻

• The C-O bond order in CO₂ is 1.5 and in [CO₃]²⁻ it is 1.33

The molecular geometry of XeOF₄ molecule is:

• Trigonal bipyramidal

• Octahedral

• "see-saw" geometry

• Square Pyramidal

Gillespie geometry (electron group geometry) of XeO₂F₂ is:

• AX₄E

• AX₄

• AX₄E₂

• AX₃E₂

Indicate which of the following molecules is polar:

• PCl₅

• CO₂

• PCl₃

• C₂H₄