d and f BLOCK ELEMENTS

What causes the structural variability observed in actinoid metals?

• Their high melting points
• Their radioactivity
• Irregularities in metallic radii which are greater than in lanthanoids
• Their similar densities

What is a general characteristic of the appearance of actinoid metals?

• They are brightly colored
• They are dull and black
• They are silvery in appearance
• They are transparent

Why is it considered unsatisfactory to review actinoid chemistry solely based on oxidation states?

• Oxidation states are difficult to measure
• All actinoids have the same oxidation states
• Oxidation states are not important for actinoids
• The distribution of oxidation states is uneven and different for earlier and later elements

In which part of the actinoid series are higher oxidation states (+4, +5, +6, +7) more commonly observed?

• Last half
• Throughout the entire series
• First half
• Only in the middle elements

What is the most common oxidation state exhibited by actinoids?

• +2
• +3
• +4
• +5