P.3.2.2.3 Energy levels and photon emission

The diagram shows an energy-level diagram for a hydrogen atom. Electrons, each having a kinetic energy of 2.0 × 10^–18 J, collide with atoms of hydrogen in their ground state. Photons are emitted when the atoms de-excite.

How many different wavelengths can be observed with incident electrons of this energy?

• 1

• 3

• 6

• 7

Which statement suggests that electrons have wave properties?

• Electrons are emitted in photoelectric effect experiments.

• Electrons are released when atoms are ionised.

• Electrons produce dark rings in diffraction experiments.

• Electron transitions in atoms produce line spectra.

The diagram shows an energy level diagram for a hydrogen atom.

Electrons with energy 13.0 eV collide with atoms of hydrogen in their ground state.

What is the number of different wavelengths of electromagnetic radiation that could be emitted when the atoms de-excite?

• 0

• 3

• 6

• 7

The values of the lowest three energy levels in a particular atom are shown in the table. The diagram shows these levels together with the ground state of the atom.

When an electron moves from level 3 to level 1, radiation of frequency 6.2 × 10¹⁴ Hz is emitted. What is the frequency of the radiation emitted when an electron moves from level 2 to level 1?

• 2.3 × 10¹⁴ Hz

• 3.5 × 10¹⁴ Hz

• 4.6 × 10¹⁴ Hz

• 8.3 × 10¹⁴ Hz

The diagram shows the four lowest energy levels for an electron in an atom. P, Q, R and S represent, to scale, the relative energy values of these energy levels.

An electron transition from level R to level Q is accompanied by the emission of a photon of visible light.

Which electron transition would be accompanied by the emission of a photon of infrared radiation?

• S to R

• S to Q

• Q to P

• R to P

The diagram gives some of the energy levels of a hydrogen atom. The transition of an excited hydrogen atom from E₃ to E₁ causes a photon of visible light to be emitted.

Which transition causes a photon of ultraviolet light to be emitted?

• E₄ to E₃

• E₃ to E₂

• E₂ to E₁

• E₁ to E₀

The diagram drawn to scale shows some of the energy levels of an atom. Transition P results in the emission of a photon of wavelength 4 × 10^–7 m.

Which one of the transitions A, B, C, or D could result in the emission of a photon of wavelength 8 × 10^–7 m?

• A

• B

• C

• D

The diagram shows some of the energy levels for a hydrogen atom.

A free electron of kinetic energy 20.0 × 10^–19 J collides with a hydrogen atom in its ground state. The hydrogen atom is excited from its ground state to the first excited state. The kinetic energy of the free electron after the collision is

• 1.8 × 10^–19 J

• 3.6 × 10^–19 J

• 5.4 × 10^–19 J

• 16.4 × 10^–19 J

The diagram shows some energy levels of an atom.

The transition E₃ to E₁ corresponds to the emission of visible light.

A transition corresponding to the emission of infrared radiation could be

• E₁ to E₀

• E₄ to E₁

• E₁ to E₂

• E₃ to E₂