m = 0.0275 nm .
E = hc/λ or λ = hc/E = (6.626 x 10-34 Js)(2.99 x 108 m/s)/(8.1 x 10-17 J) λ = 2.44 x 10-9 m = 2.44 nm , which is about 5 times too big!
The correct option is (A) 0.12 .
(b) K = 100 eV = 1.6 × 10−17 J. From de Broglie, λ = h/p = h/√2mK = 0.123 nm . From diffraction, asinθ = mλ.
Thus the wavelength of a photon of energy 1eV is 12.4×103 .
Apply the de Broglie wave equation λ=hmv λ = h m v to solve for the wavelength of the moving electron.
Answer: De-Broglie’s wavelength(say ¥) is (h/mv) where h=Planck’s Constant,m=mass and v=velocity. As we know, mv=momentum(p) or p=√(2Km) where K is kinetic energy. Put ¥=5000*(10^-10) and value of h and m=9.1*(10^-31) and get the value of K.
Wavelength is an important parameter of waves and is the distance between two like points on the wave. The wavelength is calculated from the wave speed and frequency by λ = wave speed/frequency, or λ = v / f . A peak is the highest point of a wave, while the valley is the lowest point of a wave.
Thus wavelength of the given electron of kinetic energy of 120 eV is 4.5 ×10^-20 m .
Electron, lightest stable subatomic particle known. It carries a negative charge of 1.602176634 × 10 − 19 coulomb, which is considered the basic unit of electric charge. The rest mass of the electron is 9.1093837015 × 10 − 31 kg , which is only 1 / 1,836 the mass of a proton.
Equal to the initial energy .
Calculate de Broglie wavelength of an electron travelling at 1 % of the speed of light. Wavelength of electron (λ)=hmυ=(6.626×10-34kgm2s-1)(9.1×10-31kg)×(3×106ms-1)= 2.43×10-10m .
Explanation: An electron is a negatively charged subatomic particle that can be either free which means not attached to any atom or bound to the nucleus of an atom. ... Therefore, the momentum of an electron of energy 100 eV is 1.227 × 10^{-10} m .
Energy is often measured in electronvolts. This equation only holds if the wavelength is measured in micrometers. The photon energy at 1 μm wavelength, the wavelength of near infrared radiation, is approximately 1.2398 eV.
| Energy Level Energy | 5 – 2.176 eV |
|---|
Applications of de Broglie Waves
10 eV electrons (which is the typical energy of an electron in an electron microscope): de Broglie wavelength = 3.9 x 10 – 10 m . This is comparable to the spacing between atoms.
