MCQ
If $n=2$ for $H e^{+}$ ion than ...........$\mathop A\limits^o $ out the wave length
  • $3.33$
  • B
    $6.42$
  • C
    $1.47$
  • D
    $2.37$

Answer

Correct option: A.
$3.33$
a
Asn $=2$ and $Z =2$ for $He ^{+}$ ion, so the wave length is calculated below.

$2 \pi r = n \lambda \quad \because r=0.529 \frac{ n ^{2}}{ Z }$

$2 \pi \times 0.529 \frac{ n ^{2}}{ Z } A = n \lambda$

$\lambda=\frac{2 \times 3.14 \times 0.529 \times 2}{2} A$

$\lambda=3.33\,\mathop A\limits^o $

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