Calculate the energy change that would accompany an electronic transition in a hydrogen atom from n = 2 to n = 3 shell. also, determine whether radiation is absorbed or emitted during this transition.

The energy associated with this transition is 3.04 × 10⁻¹⁹ J.

Explanation:

An electron absorbs radiation when it goes from level 2 to level 3. The wavelength associated to this transition can be calculated using Rydberg equation.

where,

λ is the wavelength of the radiation

RH is the Rydberg constant for Hydrogen (1.10 × 10⁷ m⁻¹)

n₁ and n₂ are the levels (being n₁ < n₂)

In this case,

We can calculate the energy associated to this radiation using Planck-Einstein equation.

E = h . ν = h . c / λ

where,

h is the Planck's constant (6.63 × 10⁻³⁴ J.s)

c is the speed of light (3.00 × 10⁸ m/s)

Then,

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.