d and f BLOCK ELEMENTS

Why are the 5f electrons in actinoids more effectively shielded than the 4f electrons in lanthanoids?

• Because 5f orbitals are larger.
• Because 5f electrons have higher energy.
• Because 5f orbitals penetrate less into the inner electron core.
• Because 5f electrons are farther from the nucleus on average.

What is the main factor causing the actinoid contraction being greater than the lanthanoid contraction?

• Actinoids have more protons.
• Actinoids have fewer electrons.
• Poorer shielding effect of 5f electrons compared to 4f electrons.
• Actinoids have larger nuclei.

What is a key characteristic of the reaction between actinoid metals and most non-metals?

• It requires very high temperatures.
• It only occurs in aqueous solutions.
• It occurs at moderate temperatures.
• It is instantaneous at room temperature.

Which metals are specifically mentioned as being required by the battery industry?

• Li and Co
• Fe and Pb
• Al and Cu
• Zn and Ni/Cd

Why are the elements of Group 11 still referred to as coinage metals?

• Because they are the most expensive metals.
• Because they are liquids at room temperature.
• Due to their historical use in making coins.
• Because they are highly radioactive.