Radio waves have the longest wavelengths
When light travels from a medium with higher refractive index to a medium with lower refractive index, there is a critical angle after which all the light is reflected (so, there is no refraction).
The value of this critical angle can be derived by Snell's law, and it is equal to

where n2 is the refractive index of the second medium and n1 is the refractive index of the first medium.
In our problem, n1=1.47 and n2=1.33, so the critical angle is
Answer: 
The chromium nucleus will complete the reaction.
Explanation:
The given reaction is a type of radioactive nuclei decay:
Positron emission: It is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. This is also known as
-decay. In this the mass number remains same.

Now according to the given reaction:

The chromium nucleus will complete the reaction.