Question

An electron has kinetic energy equal to100ev then calculate momentum

Answer 1

Answer:

Explanation:

Energy is E=100eV=100×1.6×10(-19 power of 10)  

joule=1.6×10( -17 power of 10)

Joule

Now its momentum will be p= 2

2mE

​ putting the mass of electron as m=9.1×10(-31 power of 10)kg  

we get p=5.4×10( -24 power of 10)kgms

The de-broglie wavelength will be given by λ= h/p

put the value of Plank's constant as h=6.62×10( -34 power of 10)

Js and the value of p  

we get λ=1.22×10 (-10 power of 10)  

m=1.22A  

Answer 2

Explanation:

Kinetic energy K =p^2/2m

Thus momentum p = sqrt(2mK)

So, p = sqrt (2*9.1*10^-31*100*1.6*10^-19)

= sqrt(29.12*10^48)

= 5.4*10^-24 kg. m/sec