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🧪 Chemistry  ·  Classification of Elements and Periodicity in Properties  ·  NEET & JEE

Ionisation energy shows a dip between Group 2 and Group 13 because:

Answer: The p orbital electron is easier to remove than the s orbital electron.

  • A The p orbital electron is easier to remove than the s orbital electron
  • B Group 13 elements simply have more protons in the nucleus
  • C Group 2 elements experience unusually higher electron shielding
  • D The extra electron in Group 13 is added to an inner shell

Correct answer: A. The p orbital electron is easier to remove than the s orbital electron

Explanation: Going from Group 2 (s<sup>2</sup>) to Group 13 (s<sup>2</sup>p<sup>1</sup>), the p electron is higher in energy and more shielded than the s electrons.

The complete modern periodic table showing all 118 elements with atomic number, symbol, and atomic mass, color-coded by element category

The complete modern periodic table (118 elements). Image: Cepheus et al., Public Domain, via Wikimedia Commons.

Concept context

The periodic table organises all 118 elements by atomic number and similar properties. Study periodic trends like atomic radius, ionization energy, and electronegativity, and learn how an element's position predicts its behaviour.

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