Practice portal › Dual Nature of Matter and Radiation › Einstein's Photoelectric Equation and Work Function

The work function of ______ is the lowest.

Asked in GSEB Board March 2020 · Work function and the photoelectric equation

Answer: (2) Caesium

Step-by-step solution

Idea: an alkali metal holds its single outer electron loosely, so its work function is small.

Typical values: caesium ≈ 2.14 eV, copper ≈ 4.65 eV, nickel ≈ 5.15 eV, platinum ≈ 5.65 eV.

Caesium's is the lowest, which is why caesium is used in photocells that must respond to visible light.

So the work function of caesium is the lowest.

Why the other options are wrong

More Einstein's Photoelectric Equation and Work Function questionsAll Einstein's Photoelectric Equation and Work Function questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer