Question

Assertion (A): In the experiment of
a-particle scattering extremely
thin gold foil is preferred.
Reason (R): Gold is ductile material.
(1) Both 'A' and 'R' are true and 'R
is the correct explanation of 'A'.
(2) Both 'A' and 'R' are true but 'R
is not correct explanation of 'A'.
(3) 'A' is true and 'R' is false.
(4) Both 'A' and 'R' are false.​

Answer 1

Answer:

Solution:

For first line of Lyman series n1=1,n2=2n1=1,n2=2

∴1λ=Z2R34∴1λ=Z2R34

In the case of hydrogen atom,

Z=1,1λ=R34Z=1,1λ=R34

For hydrogen-like atom,

Z=11,1λ′=121R34Z=11,1λ′=121R34

⇒λ′λ=3R4×4121R×3⇒λ′λ=3R4×4121R×3

⇒λ′=λ121⇒λ′=λ121

=1210121=10Å