The answer & explanation for this question is given in the attachment below.
Answer:

Explanation:
h = Planck's constant = 
c = Speed of light = 
E = Energy = 
Wavelength ejected is given by

The maximum wavelength in angstroms of the radiation that will eject electrons from the metal is 
Answer: you cant see sound waves but youcan defiently hear them . when the travle through difrent levels they depend on how loud the sound wave is if you hear a loud sound its called a loud sound wave
Explanation: