Inorganic Chemistry

Which of the following is NOT a form of electromagnetic radiation?

• Beta radiation

• Gamma radiation

• Ultra-violet radiation

• Infra-red radiation

Compared to visible radiation, ultra-violet radiation has

• longer wavelength and higher velocity

• higher frequency and longer wavelength

• lower frequency and shorter wavelength

• shorter wavelength and higher frequency

Which of the following lists electromagnetic radiation bands in order of increasing frequency?

• Ultraviolet, visible, infra-red, radio

• Radio, infra-red, visible, ultraviolet

• Radio, microwave, ultraviolet, visible

• Visible, ultraviolet, X-ray, microwave

Which area of the electromagnetic spectrum has the longest wavelength?

• Red light

• Radio waves

• X-rays

• Blue light

Light from a sodium street lamp is found to have a frequency of 5.09 x 10¹⁴ Hz. Calculate the wavelength of this light in nanometres.

Answer explanation

589 nm

Potassium compounds produce a lilac colour when heated in a bunsen flame. Use the data booklet to find the wavelength of the light associated with potassium and calculate the frequency of this radiation.

Answer explanation

7.4 x 10¹⁴ Hz

When hydrogen is subjected to a high voltage in a gas discharge tube and the emitted light is passed through a prism the atomic emission spectrum produced is as shown below.

Explain how the lines on the spectrum are produced.

To cause caesium atoms on the metal surface to lose electrons energy equivalent to 200 kJ mol⁻¹ must be supplied. Calculate the wavelength of light, in nanometres, that will cause caesium to lose electrons.

Answer explanation

599 nm

The following technique is used to detect trace elements in steels and other alloys. The metal sample is sparked as shown in the diagram.

The output of one sample is also shown.

In which region of the electromagnetic spectrum do these lines lie?

Calculate the energy, in kJ mol⁻¹, of the line due to tin.