Carbon tetrahydride is B. CH4
Well my thinking is that the lighter the slower the water evaporates or the darker the faster becuase dark colors absorb light and allows a lot of heat to be generated or not at all.
Explanation:
Given that,
The mean kinetic energy of the emitted electron, 
(a) The relation between the kinetic energy and the De Broglie wavelength is given by :



(b) According to Bragg's law,

n = 1
For nickel, 



As the angle made is very small, so such an electron is not useful in a Davisson-Germer type scattering experiment.
Answer:
When waves overlap in-phase (crest meets crest or trough meets trough) the waves energy is additive and the amplitude increases.
Explanation:
When waves overlap out-of-phase (crest meets trough) the waves cancel and the amplitude (energy) decreases. When two interfering waves cancel each other out.