d and f BLOCK ELEMENTS MCQ Quiz: GKFix - Bridge of Knowledge

Question 66

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What is the electronic configuration of the element with atomic number 61 (Promethium)?

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How does the chemical reactivity of early actinoids (e.g., Ac, Th, Pa, U) compare to that of lanthanoids?

Early actinoids are less reactive than lanthanoids.
Early actinoids are generally more reactive than lanthanoids, showing greater similarity to transition metals.
Reactivity is similar for both series.
Lanthanoids are more reactive due to their larger atomic sizes.

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How do the common oxidation states of actinoids compare to those of lanthanoids?

Both primarily show +3 and +4.
Lanthanoids primarily show +3, with some showing +2 or +4. Actinoids show a wider range of oxidation states, including +3, +4, +5, +6, and +7.
Actinoids primarily show +3, with some showing +4 or +5.
Lanthanoids show more variable oxidation states than actinoids.

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In what key ways do the electronic configurations of actinoids differ from those of lanthanoids?

Actinoids fill 6d orbitals, while lanthanoids fill 4f orbitals.
Actinoids fill 5f orbitals, while lanthanoids fill 4f orbitals. Actinoid configurations are often more variable and less predictable.
Lanthanoids have more variable configurations.
There is no significant difference.

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Which lanthanoid elements are known to commonly exhibit a +2 oxidation state, and what feature of their electronic configuration contributes to this?

Ce (Cerium) and Pr (Praseodymium); achieving a stable [Xe] core.
Eu (Europium) and Yb (Ytterbium); achieving stable filled 4f^7 (Eu^2+) or filled 4f^14 (Yb^2+) subshells.
All lanthanoids can exhibit +2.
Only Samarium (Sm); due to its specific atomic number.