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प्रश्न
The groups 1 and 2 constitute the ______ block.
विकल्प
s
p
d
d
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उत्तर
The groups 1 and 2 constitute the s block.
Explanation:
The Modern Periodic Table is divided into blocks based on which orbital the valence electrons enter. Groups 1 and 2 are called the s-block because their outermost electrons enter the $ns$ orbital.
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