Answer :
Answer : The velocity of an electron is, [tex]6.1\times 10^{6}m/s[/tex]
Explanation :
According to de-Broglie, the expression for wavelength is,
[tex]\lambda=\frac{h}{p}[/tex]
and,
[tex]p=mv[/tex]
where,
p = momentum, m = mass, v = velocity
So, the formula will be:
[tex]\lambda=\frac{h}{mv}[/tex] .............(1)
where,
h = Planck's constant = [tex]6.626\times 10^{-34}Js[/tex]
[tex]\lambda[/tex] = wavelength = [tex]1.2\times 10^{-10}m[/tex]
m = mass of electron = [tex]9.11\times 10^{-31}kg[/tex]
v = velocity of electron = ?
Now put all the given values in formula 1, we get:
[tex]1.2\times 10^{-10}m=\frac{6.626\times 10^{-34}Js}{(9.11\times 10^{-31}kg)\times v}[/tex]
[tex]v=6.1\times 10^{6}m/s[/tex]
Thus, the velocity of an electron is, [tex]6.1\times 10^{6}m/s[/tex]