It's the sound before the lightning because sound travels faster than light.
Answer:
7.0*10-11m or 70Å
Explanation:
From Bragg's equation, w=2dsinx/n
Since all the parameters are specified in the question, we can easily go ahead to obtain the wavelength but we must convert the spacing given in angstroms to meters using the conversion factor provided as shown in the solution below:
Its the second one. Add the exponents and you'll get 7
Explanation:
a) 4P + 3O2 --> 2P2O3
b) The chemical reaction above limits the number of molecules of P2O3 produced for every 4 atoms of P.