d and f BLOCK ELEMENTS

Do La³⁺ and Lu³⁺ ions show color?

• Yes, they are strongly colored
• Sometimes, depending on the compound
• No, they do not show any color
• Only La³⁺ is colorless

Why are many trivalent lanthanoid ions colored in the solid state and aqueous solutions?

• Presence of d electrons
• Presence of s electrons
• Presence of f electrons
• Presence of p electrons

What is generally observed about the density and other properties of lanthanoids across the series?

• They change erratically
• They remain constant
• They change smoothly
• They fluctuate randomly

How do lanthanoids conduct heat and electricity?

• They are poor conductors
• They are good conductors
• They are insulators
• They are semiconductors

What is the crystal structure of lanthanoids?

• Ionic crystal structure
• Covalent network structure
• Typical metallic structure
• Molecular crystal structure