Question

What is the velocity of an electron that has a de Broglie wavelength approximately the length of a chemical bond? Assume this length to be 1.2 * 10-10m.

Answer 1

Answer : The velocity of an electron is,
`6.1* 10^(6)m/s`

Explanation :

According to de-Broglie, the expression for wavelength is,

`\lambda=(h)/(p)`

and,

`p=mv`

where,

p = momentum, m = mass, v = velocity

So, the formula will be:

`\lambda=(h)/(mv)` .............(1)

where,

h = Planck's constant =
`6.626* 10^(-34)Js`

`\lambda` = wavelength =
`1.2* 10^(-10)m`

m = mass of electron =
`9.11* 10^(-31)kg`

v = velocity of electron = ?

Now put all the given values in formula 1, we get:

`1.2* 10^(-10)m=(6.626* 10^(-34)Js)/((9.11* 10^(-31)kg)* v)`

`v=6.1* 10^(6)m/s`

Thus, the velocity of an electron is,
`6.1* 10^(6)m/s`