IIT-JEE 2011 · Paper 1 · Chemistry Q20

← IIT-JEE 2011 · Paper 1

ChemistryInteger+4Question 20 of 69

The work function ( $\phi$ ) of some metals is listed below. The number of metals which will show photoelectric effect when light of 300 nm wavelength falls on the metal is

Metal	Li	Na	K	Mg	Cu	Ag	Fe	Pt	W
$\phi$ (eV)	2.4	2.3	2.2	3.7	4.8	4.3	4.7	6.3	4.75

Your answer

Answer and worked solution

Official answer: 4

Photon energy. $\dfrac{1240}{300}=4.13$ eV.

Metals with φ < 4.13 eV: Li (2.4), Na (2.3), K (2.2), Mg (3.7): four.

Answer: 4

Topics:Photoelectric effect and spectra

← Previous question Next question →

IIT-JEE 2011 · Paper 1, Chemistry question 20