Moderate
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Question
How is ionic bond formed in sodium fluoride? (The atomic number of F and Na are 9 and 11 respectively).
OR
C has 4 electrons in its outermost shell and O has 6 electrons in its outermost shell. Draw the Lewis dot diagram of CO2 molecule.
WBBSE
Class X
Physical Science
Ionic and Covalent Bond
02 Mark
2022
Answer
In sodium fluoride (NaF), an ionic bond forms through the transfer of electrons:
- Sodium (Na) loses one electron (2, 8, 1 → 2, 8) to become Na+.
- Fluorine (F) gains one electron (2, 7 → 2, 8) to become F–.
The electrostatic attraction between Na⁺ and F⁻ creates the ionic bond in NaF.

OR
Lewis dot diagram of CO2 molecule:

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