Answer:
4
Explanation:
Relationship between wavenumber and Rydberg constant (R) is as follows:

Here, Z is atomic number.
R=109677 cm^-1
Wavenumber is related with wavelength as follows:
wavenumber = 1/wavelength
wavelength = 253.4 nm

Z fro Be = 4

Therefore, the principal quantum number corresponding to the given emission is 4.
Substances that cannot be separated and found on a periodic table are elements.
Oxygen for complete combustion
Answer:
1. -4
2. +1
3. 0
4. +4
5. -2
6. +1
7. -2
reduced = H
oxidized = O
Explanation:
Know oxidation rules.
- Hope this helped! Please let me know if you would like to learn this. I could show you the rules and help you work through them.