CAIE A-Level Physics A2 22.4.3 Hf E1 E2 Questions

[Maximum number: 4]

Fig. 8.1 shows the lowest four energy levels of an electron in an isolated atom.

Fig. 8.1

Fig. 8.2 shows the lines in the emission spectrum of the atom that correspond to the transitions of the electron from n=3 to n=1 and from n=4 to n=1.

Fig. 8.2

(a)

Explain, with reference to photons, why there is a single frequency of electromagnetic radiation that corresponds to each of these transitions.

[ 2 ]

(b)

The frequency of radiation represented by line A is $f_{\mathrm{A}}$ . The frequency of radiation represented by line B is $f_{\mathrm{B}}$ . The energy of the ground state (n=1) is $E_{1}$ .

Determine an expression, in terms of $f_{\mathrm{A}}, f_{\mathrm{B}}, E_{1}$ and the Planck constant h, for the energy $E_{3}$ of the energy level n=3.

E_{3}=

[ 2 ]

E=h f
$E_{3}=E_{1}+h\left(f_{\mathrm{A}}+f_{\mathrm{B}}\right)$

CAIE A-Level Physics A2 22.4.3 Hf E1 E2 Topic Practice

Question 1

Question (a)

Question (b)