Question

The work function for Al, K and Pt is 4.28 eV,2.30 eV and 5.65 eV respectively. Their respective threshold frequencies would be ;

• A. Pt>Al> K
• B. Al>PT> K
• C. k>Al>Pt
• D. Al>K> Pt

Answer 1

Answer: (A)

Pt>Al> K

Answer 2

: Work function $\phi _ { 0 } = h v _ { 0 }$

Where is the threshold frequency

So $\phi _ { 0 } \propto v _ { 0 }$

Hence pt>Al>K