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: D
Explanation:
I assume you meant
.
- The atomic mass of potassium is 39.0983 g/mol.
- The atomic mass of sulfur is 32.065 g/mol.
- The atomic mass of oxygen is 15.9994 g/mol.
So, the formula mass of potassium sulfate is 2(39.0983)+32.065+4(15.9994)=174.2592 g/mol.
So, 5.00 moles have a mass of (5.00)(174.2592), which is about <u>870 g</u>
The Beer-Lambert law states that A = E*c*l where A is absorbance, E is the molar absorbance coeffecient, c is concentration and l is path length. Therefore the absorbance is directly proportional to concentration, and by increasing the concentration by a factor of 3, absorbance will increase by a factor of 3 giving A = 1.584