Question

What is velocity of electron in the 4th
orbit of Li2+ ion
A
1
1.095 10ºms-
B
8.6 10ms
C 8.6 x 10ms-1
D
1.64 x 10 ms -1​

Answer 1

Explanation:

V of H

2

⊕

=

nh

2πZe

2

or V α

n

Z

∴ V H

2

⊕

α 1 (Z = 1, n = 1)

V of Li

2+

α

3

3

α 1 (Z = 3, n = 3)

Therefore, velocity of e

−

in the third orbit of Li

2+

is the same velocity of an e

−

in the first orbit of H atom

Answer 2

Answer:

The correct option is (D) $1.64*10^{6} ms^{-1}$.

Calculation:

The formula to calculate the velocity of an electron is:

$v = \frac{2.188 * 10^{6} Z}{n}m/s$

Where,

Z is the atomic number

n is the orbit number.

The data we know:

1. Atomic number (Z) of $Li^{2+}$is 3
2. Orbit number (n) is 4

Now substitute these values in the formula,

$v = \frac{2.188 * 10^{6}*3 }{4}$

$v = 1.64*10^{6} m/s$

Conclusion:

The velocity of the electron in the fourth orbit is  $1.64*10^{6} ms^{-1}$.