Chemistry S & P Block Elements MDCAT 2018
PMDC Verified Question 80 of 104
Down the group acid-base behavior of metallic oxides of group 2 elements changes to
A
More basic
B
No change
C
Less basic
D
More acidic
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: More basic
Concept:

The basic character of a metal oxide depends on how easily the metal can release electrons (its metallic character) to form ionic bonds with oxygen.

Solution:

  • As we move down Group 2 (Alkaline Earth Metals), the atomic size increases.
  • This lowers the ionization energy, meaning the metals lose their valence electrons much more easily (metallic character increases).
  • Because they become more electropositive, the metal-oxygen bond becomes more highly ionic.
  • When these ionic oxides dissolve in water, they readily yield \( \text{OH}^- \) ions, making the oxides more basic down the group.


Why other options are incorrect:

  • The basicity does not decrease, remain unchanged, or turn acidic. Acidic oxides are typically formed by non-metals (found on the right side of the periodic table).

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