From erosion i think good luck :D
Answer:
Refer to the period table. Use the atomic mass for calculation. Multiply the atomic mass with the number of atoms. For example, Al2(SO4)3. (27 × 2) + (32 x 3) + (16 x 12) = molecular mass
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 