d and f BLOCK ELEMENTS

What was one of the main goals of Mendeleev when creating his table?

• To arrange elements by increasing atomic number.
• To create a table with equal-length periods.
• To group elements with similar properties in the same vertical column.
• To list all known elements alphabetically.

Why was Mendeleev's work on the periodic table published before Lothar Meyer's?

• Meyer's work was less accurate.
• Mendeleev had better connections.
• Mendeleev published his findings first.
• Meyer's work was incomplete.

What was a key difference between Mendeleev's and Lothar Meyer's classification systems?

• Meyer's system was based on atomic numbers.
• Mendeleev's system used fewer properties.
• Meyer's system had more gaps.
• Mendeleev's system was more elaborate and recognized the significance of periodicity.

Which property listed in Table 3.3 was correctly predicted by Mendeleev for Eka-silicon (Germanium)?

• Melting point
• Density
• Oxide formula
• Atomic weight

What did Mendeleev propose about the gaps in his table?

• They were errors in atomic weight measurements.
• They indicated unstable elements.
• They represented undiscovered elements.
• They were necessary for the table's symmetry.