What Is the Speed of the Slowest Electron That Can Excite a Hydrogen Atom?

[ke0nGz]

Homework Statement

The 1st excitation energy of hydrogen atom is 10.2 eV
electron charge- mass ratio (e/m) = 1.7 x 10 ¹¹ kg ^-1

Find speed of the slowest electron that can excite a hydrogen atom

Homework Equations

eV= 1/2 mv² = hf = hc/lamda

hf = work function energy + 1/2 mv ²

The Attempt at a Solution

Ans : 1.9 x 10⁶ms^-1

 

[ke0nGz]

ops delete this please.. just found it on another thread