Answer: High electron-electron repulsion in the compact 2p subshell of fluorine.
- A High electron-electron repulsion in the compact 2p subshell of fluorine
- B Fluorine's notably higher electronegativity value on the Pauling scale
- C Fluorine's higher first ionisation energy compared to chlorine
- D Chlorine's greater nuclear charge compared to fluorine
Correct answer: A. High electron-electron repulsion in the compact 2p subshell of fluorine
Explanation: Fluorine's extremely small 2p orbitals are already quite crowded; adding another electron causes more repulsion than in the larger 3p of Cl.
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.
Read the full Classification of Elements and Periodicity in Properties notes →