alleryStart learning →If an element has the configuration 2, 8, 8, 1, its valency and likely group are:
AValency 8, Group 18
BValency 7, Group 17
CValency 1, Group 1 (alkali metal)
DValency 2, Group 2 in general usage
Answer & Solution
Correct answer: C. Valency 1, Group 1 (alkali metal)
1. The outermost shell has just 1 electron.
2. Loss of this electron leaves a stable Ar core.
3. So valency is 1 and the element is in Group 1.
4. The element is potassium with Z = 19.
_Source: Selina Concise Chemistry ICSE Class 9, Ch 4 'Atomic Structure'_
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