Answer: Wavenumber of the radiation emitted is 
Explanation:
The relationship between wavelength and energy of the wave follows the equation:

where,
E = energy of the radiation = 
h = Planck's constant = 
c = speed of light = 
= wavelength of radiation = ?
Putting values in above equation, we get:


Thus wavenumber of the radiation emitted is 
Explanation:
Here are the answers. Do note that I had to convert the enthalpy to joules and temperature to Kelvin to make the unit for entropy work out.
Answer:NaF is ionic. NF3 is covalent. SiF4 is ionic. CaF2 is Ionic and NH4F is also ionic. Ionic compounds transfer electrons whereas covalent compounds share electrons hence the word "co". Also, ionic compounds are formed with metal and nonmetal. Where a covalent is with 2 nonmetals. Only ionic compounds would produce fluoride in water because ionic compounds can dissolve in water and covalent compounds cant.