Question

The correct order of variation in the sizes of atoms is:

• A. $Be>C>F>Ne$
• B. $Ne>F>C>Be$
• C. $Ne>Be>C>F$
• D. $F>Ne>Be>C$

Answer 1

The correct option is C $Ne>Be>C>F$

Atomic radii decreases on going from left to right in a period due to increase in Z-effective value. Z-effective increases with increase in atomic number. But noble gases form an exception to this rule as we measure their Van der Waal's radius. Van der Waal's radius is the largest as it is measured in non bonding condition. Noble gases have the maximum radii in a particular period.