d and f BLOCK ELEMENTS

Which of the following atomic numbers corresponds to an inner transition element?

• 29
• 59
• 74
• 104

What defines an inner transition element?

• An element with electrons only in s and p orbitals.
• An element whose differentiating electron enters an f-orbital.
• An element in the d-block of the periodic table.
• An element with a completely filled d-subshell.

What is a common use of the alloy Mischmetal, which contains Lanthanoid metals?

• In aircraft construction
• In electrical wiring
• In the production of flints for lighters and gas stove ignition.
• In dental amalgams

How does the chemical reactivity of Lanthanoids generally compare to that of Actinoids?

• Lanthanoids are generally more reactive than actinoids.
• Lanthanoids are generally less reactive than actinoids.
• They have identical reactivity.
• Reactivity depends solely on the specific element.

How do the atomic/ionic sizes of Lanthanoids generally change with increasing atomic number?

• They generally increase.
• They remain constant.
• They generally decrease, known as Lanthanoid contraction.
• They fluctuate randomly.