d and f BLOCK ELEMENTS

What is a key difference in the atomic/ionic radii trend between Lanthanoids and Actinoids?

• Lanthanoid contraction is greater than Actinoid contraction.
• They are identical.
• Actinoid contraction is generally greater than Lanthanoid contraction.
• There is no contraction in Actinoids.

What is the electronic configuration of Uranium (U)?

• [Rn] 5f4 7s2
• [Rn] 5f3 6d1 7s2
• [Rn] 5f2 6d2 7s2
• [Rn] 5f5 7s2

What is the electronic configuration of Thorium (Th)?

• [Rn] 5f2 7s2
• [Rn] 5f1 6d1 7s2
• [Rn] 5f0 6d2 7s2
• [Rn] 6d3 7s2

What is the electronic configuration of Actinium (Ac)?

• [Rn] 5f1 7s2
• [Rn] 5f1 6d1 7s2
• [Rn] 6d1 7s2
• [Rn] 5f0 6d0 7s2

What is the electronic configuration of Gadolinium (Gd)?

• [Xe] 4f8 6s2
• [Xe] 4f7 5d1 6s2
• [Xe] 4f6 5d2 6s2
• [Xe] 4f9 6s2