Table 28.5 shows the work functions of several different metals.

a. State which metal requires the highest frequency of electromagnetic waves to release electrons.b. State which metal will release electrons when the lowest frequency of electromagnetic waves is incident on it?
c. Calculate the threshold frequency for zinc.
d. Calculate the threshold wavelength for potassium.

You will need these values to answer question:
Speed of light in a vacuum c = 3.00 × 108 m s⁻¹
Planck constant h = 6.63 × 10⁻³⁴ J s
Mass of electron m_e = 9.11 × 10⁻³¹ kg
Elementary charge e = 1.60 × 10⁻¹⁹ C

Transcribed Image Text:

Metal Work function /J Work function / eV caesium 3.0 x 10-19 1.9 calcium 4.3 x 10-19 2.7 gold 7.8 x 10-19 4.9 potassium 3.2 x 10-19 2.0 zinc 6.9 x 10-19 4.3