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 
Sound waves are most effective when traveling through solids. Less effective when in liquids and least effective in air.
Answer:
6.
2AI2O3 + heat -> 4AI + 3O2
Reaction type: Combustion
7.
2AI+ 6HCl -> 3H2 + 2AlCl3
Reaction type: Single Replacement
8.
IDK
Reaction type: Double Replacement?
Explanation:
Answer:
N- 1s2 2s2 2p3
Mg- 1s2 2s2 2p6 3s2
O- 1s2 2s2 2p4
F- 1s2 2s2 2p5
Al-1s2 2s2 2p6 3s2 3p1
Explanation:
Order of decreasing atomic radius
Mg,Al, N,O,F
Order of increasing ionization energy
Mg,Al, N,O,F
Reason:
Atomic radius decreases with increase in nonmetallic character. Looking at the electronic configurations, as effective nuclear charge increases, the atom becomes smaller and the attractive force between the nucleus and the outermost electrons increases. Hence, the radius of the atom decreases and ionization energy increases. Note that the addition of more orbital electrons implies addition of more nuclear charge since the both must exactly balance for the atom to remain electrically neutral. The more the electrons in the outermost shell, the higher the first ionization energy.