d and f BLOCK ELEMENTS

What is considered the fundamental basis for the modern periodic classification of elements?

• Atomic weight
• Density
• Atomic number and electronic configuration
• Melting point

What was the approximate number of elements known by 1865?

• 31
• 114
• 63
• 92

What is the primary reason given for classifying elements?

• To predict the atomic weight of elements
• To determine the density of elements
• To manage the large number of elements and their compounds
• To find new elements in nature

Who is credited with emphasizing the importance of the Periodic Table in the provided text?

• Dmitri Mendeleev
• Glenn T. Seaborg
• Henry Moseley
• John Newlands

Which of the following best describes Hund's rule of maximum multiplicity?

• Electrons fill orbitals starting with the lowest energy orbital available.
• Electrons must have opposite spins in the same orbital.
• Electrons will occupy degenerate orbitals singly before pairing up, with parallel spins.
• No two electrons can have the same set of four quantum numbers.