how to find The work function of some metals that are listed below. The number of metals which will show photoelectric effect when light of 300 nm wavelength falls on the metal .Li-2.4 Na-2.3 K-2.2 Mg-3.7 Cu-4.8 Ag-4.3 Fe-4.7 Pt-6.3 W -4.75

@ PRETTY 
for finding out the work function u need the kinetic energy. 
as per the einstein photoelectric equation 
ENERGY = WORK FUNCTION + K.E ( MAX ) 
so, by putting the value 
hc/ lambda = work function + ½ mv square 
h and c u knows and lambda is given as 300 nm . 
so, frst of all calculate energy , then put the same in ½ mv square 
m is given e, u find out and then calculate work function from their 
HOPE U CAN CALCULATE NOW 
IF NOT , THEN LET ME KNOW 
ALL THE BEST ..