d-block elements

Which block of elements are known as transition elements?

• p-block

• d-block

• s-block

• f-block

Colour of transition metal ions are due to absorption of some wavelength. This results in

• d-s transition

• s-s transition

• s-t/transition

• d-d transition

Which of the following pairs of ions have the same electronic configuration?

• Cu²⁺, Cr²⁺

• Fe³⁺, Mn²⁺

• Co³⁺, Ni³⁺

• Sc³⁺, Cr³⁺

Lanthanoid contraction occurs due to an increase in

• ionization enthalpy

• effective nuclear charge

• atomic radius

• electron shield

Which of the following are d-block elements but not regarded as transition elements?

• Cu, Ag, Au

• Zn, Cd, Hg

• Fe, Co, Ni

• Ru, Rh, Pd

How many possible d orbitals are there in one shell?

• 10

• 5

• 7

• 14

Predict how the valence electrons in iron metal (iron 0) should be organized.

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This is iron⁰. It loses 3e^- to become iron³⁺. Use stability rules to find its new e^- config.

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Electron configuration for Cr is 4s¹3d⁵ and NOT 4s²3d⁴. Why?

• Half filled 3d orbital is most stable

• 4s¹ is more stable than 4s²

• Fully filled orbital is more stable

• Cr is a transition element

Cd and Zn are not transition elements. Why?

• 3d orbitals are empty

• 3d orbitals are partially filled

• 3d orbital are fully filled

• 3d orbitals are not partially filled either in the elemental state or in any of their

  common ions.