d and f BLOCK ELEMENTS

How does the reactivity of actinoids with boiling water demonstrate a specific chemical property?

• It shows they are unaffected by heat.
• It demonstrates their ability to reduce water.
• It proves they are noble metals.
• It indicates low reactivity.

What does the text imply about the general trend of properties in the early actinoid series?

• Properties change erratically.
• Properties are identical.
• Properties change gradually and elements are similar to each other.
• Properties depend only on atomic number.

Why is the availability of outer electrons important for the reactivity of actinoids?

• Less available electrons increase reactivity.
• It determines the melting point.
• More available electrons lead to easier participation in chemical reactions.
• It only affects physical properties.

What is the main implication of the text regarding the shielding effect of 5f versus 4f electrons?

• 4f electrons shield outer electrons better than 5f electrons.
• 5f electrons shield outer electrons better than 4f electrons.
• Both shield equally well.
• Shielding is not affected by orbital type.

How does the text describe the general chemical nature of actinoid metals?

• They are generally unreactive.
• They are moderately reactive under all conditions.
• They are highly reactive, especially in finely divided form.
• They are only reactive with oxygen.