Question

Какова кинетическая энергия и скорость фотоэлектронов ? вылетающих из натрия при облучении его светом с длиной волны 200нм.

Answer 1

кинетическая энергия  4000.                 743 фотоэлектронов

Answer 2

Kinetic Energy and Velocity of Photoelectrons emitted from Sodium

When sodium is illuminated with light of a wavelength of 200 nm, photoelectrons are emitted. The kinetic energy and velocity of these photoelectrons can be determined using the equation for the kinetic energy of a particle:

Kinetic Energy (KE) = 1/2 * mass * velocity^2

To calculate the kinetic energy and velocity of the photoelectrons, we need to know the mass of the photoelectron. The mass of an electron is approximately 9.11 x 10^-31 kilograms.

Using the equation for the kinetic energy, we can rearrange it to solve for the velocity:

Velocity = sqrt(2 * KE / mass)

Now let's calculate the kinetic energy and velocity of the photoelectrons emitted from sodium when illuminated with light of a wavelength of 200 nm.

According to source the maximum kinetic energy of photoelectrons emitted from sodium when illuminated with light of a wavelength of 200 nm is 0.65 eV.

To convert electron volts (eV) to joules, we can use the conversion factor: 1 eV = 1.6 x 10^-19 J.

Therefore, the maximum kinetic energy of the photoelectrons emitted from sodium can be calculated as follows:

KE = 0.65 eV * (1.6 x 10^-19 J/eV) = 1.04 x 10^-19 J

Now we can calculate the velocity of the photoelectrons:

Velocity = sqrt(2 * KE / mass) = sqrt(2 * 1.04 x 10^-19 J / 9.11 x 10^-31 kg) = 6.57 x 10^5 m/s

Therefore, the kinetic energy of the photoelectrons emitted from sodium when illuminated with light of a wavelength of 200 nm is approximately 1.04 x 10^-19 J, and their velocity is approximately 6.57 x 10^5 m/s.

Please note that these calculations are based on the information provided in source