d and f BLOCK ELEMENTS

Why is the +1 oxidation state relatively common for Copper (Cu) among the first transition series?

• Because it is the first transition metal.
• Because it has fewer electrons.
• Because losing one electron results in the stable, fully filled 3d10 configuration.
• Because it is highly reactive.

What is a significant environmental concern associated with some Actinoid elements?

• They are highly corrosive.
• They are non-biodegradable.
• They are expensive to mine.
• Their long half-lives and radioactivity make their waste products hazardous for extended periods.

What is a common use of Lanthanoid elements or their compounds?

• In structural steel
• In dental amalgams
• In phosphors for colour televisions and LED lights.
• In aircraft construction

What is the primary product formed when acidified potassium dichromate (K2Cr2O7) solution reacts with sulfur dioxide (SO2)?

• Sulfur trioxide (SO3)
• Sulfur (S)
• Sulfuric acid (H2SO4)
• Hydrogen sulfide (H2S)

What is the primary product formed when acidified potassium dichromate (K2Cr2O7) solution reacts with iron(II) ions (Fe2+)?

• Iron metal (Fe)
• Iron(III) ions (Fe3+)
• Iron(II) hydroxide (Fe(OH)2)
• Iron(II) oxide (FeO)