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Periodic Classification of Elements

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An atom has electronic configuration $2$, $8$, $7$.

$(a)$ What is the atomic number of this element ?

$(b)$ To which of the following elements would it be chemically similar ?(Atomic numbers are given in parentheses.)

$N(7)$ $F(9)$ $P(15)$ $Ar(18)$

Option A

Option B

Option C

Option D

Solution

$(a)$ The atomic number of this element is $17.$

$(b)$ It would be chemically similar to $F(9)$ with configuration as $2,\, 7$.

Std 10

Science

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