D I think .... don’t be mad if I’m wrong
Answer:
he wavelength is different (greater) than the wavelength of the incident photon
Explanation:
The Compton effect is the scattering of a photon by an electron, this process is analyzed using the conservation of momentum, in which we assume that initially the electron is at rest and after the collision it recedes, therefore the energy of the incident photon decreases and consequently its wavelength changes
To complete the sentence we use the wavelength is different (greater) than the wavelength of the incident photon
The answer is calcium. I just did it and it was correct
C. none of the above
An electrical conductor is a substance in which electrical charge carriers, usually electrons, move easily from atom to atom with the application of voltage. Conductivity, in general, is the capacity to transmit something, such as electricity or heat. ... Copper, steel, gold, aluminum, and brass are also good conductors.
a. 4.52 m/s south
Velocity is a vector, whose magnitude is defined as the ratio between the displacement of the object and the time taken for the displacement to occur:

where
d is the displacement
t is the time
Velocity is a vector, so it also has a direction, which corresponds to that of the displacement.
For the ball in this problem,
d = 9.5 m south
t = 2.1 s
Substituting, we find:

and the directiion is the same as the displacement (south).
b. 4.52 m/s north
For this part, we must keep in mind that the speed is the magnitude of the velocity; however, speed is a scalar, so it does not have a direction.
Here we are told that the tennis ball travels at constant speed, so on its way back from Liam to Katie the ball's velocity is still the same as before, therefore

However, this time the direction is opposite to before, since the ball is travelling in the opposite direction.
Therefore, the ball's velocity when Liam returns Katie's service is
4.52 m/s north