Question

The ratio for the speed of the electron in the 3rd orbit of He+ to the speed of the electron in the 3rd orbit of hydrogen atom will be :

• A. 1:1
• B. 1:2
• C. 4:1
• D. 2:1

Answer 1

Answer: (D)

2:1

Answer 2

We know that,
$V ∝ \frac Zn$
Then, the required ratio is
= $\frac {\frac 23}{\frac 13}$
= $2:1$

So, the correct option is (D): $2:1$