d and f BLOCK ELEMENTS

What was the experimentally determined atomic weight of Gallium when it was discovered?

• 68
• 72
• 72.6
• 70

According to the table, what was the predicted formula of the oxide for Eka-aluminium?

• EO
• E2O3
• EO2
• E2O5

What was unique about Mendeleev's approach compared to earlier attempts like Newlands' Law of Octaves?

• He used atomic numbers.
• He arranged elements alphabetically.
• He focused only on physical properties.
• He recognized varying period lengths and left gaps for undiscovered elements.

Which scientist's work on periodicity was published after Mendeleev's, despite being developed concurrently?

• Dmitri Mendeleev
• John Newlands
• Jons Jakob Berzelius
• Lothar Meyer

What did Mendeleev think about the atomic weight measurements of elements that didn't fit his scheme?

• They were perfectly accurate.
• They were irrelevant.
• They might be incorrect.
• He ignored atomic weights entirely.