(a) (i) Define atomic spectra. (ii) Differentiate between emission spectra and absorption spectra. (b) The diagram above illustrates an electron transition from energy level n = 3 to n = 1. Calculate the: (i) energy of the photon (ii) frequency of the photon (ii) wavelength of the photon [h = 6.6 x 10\(^{-34}\)J s, c = 3.0 x 10\(^8\) ms\(^{-1}\); 1 ev = 1.6 x 10\(^{-19}\) J] c)(i)Differentiate between soft x-rays and hard x-rays (ii) Draw the circuit symbol for a p-n junction diode. (iiii) Give the reason for doping a semiconductor material

Monday, 07 April 2025

Register • Login

(a) (i) Define atomic spectra. (ii) Differentiate between emission spectra and ...

Trending Questions

** Free JAMB 2025 CBT Practice **

In a federal system,the essence of specifying the constitutional relationship between ...

Abraham circumcised his son,Isaac, on the eight days because

In mammals, the exchange of nutrients and metabolic products occurs in the

The problems of conducting census include?

Take Free Practice Test On 2025 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE

(a) (i) Define atomic spectra.
(ii) Differentiate between emission spectra and absorption spectra.
(b)

The diagram above illustrates an electron transition from energy level n = 3 to n = 1. Calculate the:
(i) energy of the photon
(ii) frequency of the photon
(ii) wavelength of the photon [h = 6.6 x 10

^{- 34}

J s, c = 3.0 x 10

^{8}

^{- 1}

; 1 ev = 1.6 x 10

^{- 19}

J]

c)(i)Differentiate between soft x-rays and hard x-rays
(ii) Draw the circuit symbol for a p-n junction diode.
(iiii) Give the reason for doping a semiconductor material

Explanation

(a) The emission of light from a substance when its excited electrons move to a lower energy level.
OR
Distinct/separate bright lines of light of definite frequency/wavelength (emitted from vapourised atoms)
(ii) Emission spectra is the pattern of light displayed when electrons jump from a higher energy level to a lower energy level, while absorption spectra is the displayed pattern of wavelengths absorbed by the gas.

(b)

Δ

E = E

_{i}

- E

_{f}

= -1.51 + 13.6
= 12.09 eV
= 12.09 x 1.6 x 10

^{- 19}

J
= 1.934 x 10

^{- 18}

J
(ii)

Δ

E- hf
f =

\frac{Δ E}{h}

\frac{1.934 \times 10^{- 18}}{6.6 \times 10^{- 34}}

f = 2.93 x 10

^{15}

Hz

(ii) c = f

λ

λ

\frac{3 \times 10^{8}}{2.93 x 10^{13}}

= 1.023 x 10

^{- 7}

m

(c) (I) Soft x-rays are those with longer wavelengths/lowNer penetrating/less energy while hard x-rays are those with shorter wavelengths/higher penetrating power more energy.

(iii) To increase the electrical conductivity/reduce electrical resistivity of the semiconductor.

Prev Current Next

STAY UPDATED
FOLLOW US ON :

Facebook

Register • Login