d and f BLOCK ELEMENTS

Why are the magnetic properties of actinoids described as more complex than those of lanthanoids?

• Actinoids have more unpaired electrons.
• Actinoids are radioactive.
• The involvement and behavior of 5f electrons are more complex.
• Lanthanoids have no magnetic properties.

How do actinoid metals behave when exposed to alkalies (strong bases)?

• They react vigorously to produce hydrogen.
• They dissolve completely.
• They show no reaction.
• They form complex salts.

What explains the difference in reactivity between hydrochloric acid and nitric acid towards actinoid metals?

• HCl is a weaker acid.
• HNO3 is a weaker acid.
• Nitric acid causes formation of protective oxide layers.
• Actinoids dissolve completely in both.

Why does boiling water react with actinoid metals to form a mixture of oxide and hydride?

• Because water is a strong acid.
• Because actinoids are non-metals.
• It demonstrates their high chemical reactivity.
• Because they are noble metals.

What is the primary reason actinoids are considered highly reactive metals?

• Due to their large atomic size.
• Due to their low melting points.
• Due to less firmly held outer electrons.
• Due to their high electronegativity.