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.
Answer:
B, D, C
Explanation:
the solution may have more than one solute, a solution is a homogenous mixture of 2 or more substances and not all solutions are liquid
Hello!
The center of an atom is called the nucleus; it is comprised of protons and neutrons, collectively known as nucleons. The electrons float around the nucleus in a cloud.
Answer:
A) Protons and neutrons are in the center of the atom, and electrons move around in the cloud.
Answer: You started with 8
Explanation: the amount of products is equal to the amount of reactants