Question

The mass of an electron is 9.1×10-31 kg. If it’s kinetic energy is 3.0×10-25J, calculate it’s wavelength.​

Answer 1

ʜᴏᴘᴇ ᴛʜɪs ʜᴇʟᴘs ʏᴏᴜ

ᴍᴀʀᴋ ᴀs ʙʀᴀɪɴʟɪᴇsᴛ

Answer 2

Answer:-

9.02×10⁻⁷m

Explanation:-

We know that :-

=> K.E. = 1/2mv²

So, firstly let's calculate the velocity of the electron.

=> 3×10⁻²⁵ = 1/2×9.1×10⁻³¹×v²

=> v² = [3×10⁻²⁵×2]/[9.1×10⁻³¹]

=> v² = 0.65×10⁶

=> v² = 6.5×10⁵

=> v = √650000

=> v = 806.22m/s

Now , we know that:-

=> λ = h/mv

• Planck's Constant (h) = 6.62×10⁻³⁴J

=> λ = 6.62×10⁻³⁴/[9.1×10⁻³¹×806.22]

=> λ = 6.62×10⁻³⁴/7336.6×10⁻³¹

=> λ = [6.62×0.001]/7336.6

=> λ = 9.02×10⁻⁷ m

Thus, wavelength of the electron is 9.02×10⁻⁷m.