Question

Plese HELP I AM NEW

On the basis of Bohr's model, the radius of the 3rd orbit
is -
(A) Equal to the radius of first orbit
(B) Three times the radius of first orbit
(C) Five times the radius of first orbit
(D) Nine time the radius of first orbit​

Answer 1

The correct answer is option D.

Step-by-step explanation:

Formula used for the radius of the
`n^(th)` orbit will be,

`r_n=(n^2* 52.9)/(Z)` (in pm)

where,

`r_n` = radius of
`n^(th)` orbit

n = number of orbit

Z = atomic number

Radius of the first orbit, n = 1

`r_1=(1^2* 52.9)/(Z)=(1* 52.9)/(Z)`..[1]

Radius of the third orbit, n = 3

`r_3=(3^2* 52.9)/(Z)=(9* 52.9)/(Z)`..[2]

[1] ÷ [2]

`(r_1)/(r_3)=((1* 52.9)/(Z))/((9* 52.9)/(Z))`

`r_1* 9=r_3`

The radius of the 3rd orbit is nine times the radius of first orbit.

Answer 2

`\boxed{\text{(D) Nine times the radius of the first orbit}}`

Step-by-step explanation:

On the basis of Bohr's model, the radius of the nth orbit is

r = a₀n²

where a₀ is a constant called the Bohr radius.

r₃\r₁ = (a₀ × 3)²/(a₀ × 1)² = 9/1 = 9

The radius of the third Bohr orbit is nine times the radius of the first orbit.