Ans: As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit will <u>increase.</u>
The energy (E) is related to the frequency (ν) by the following equation:
E = hν
where h = planck's constant
The change in energy i between levels is:
ΔΕ = h(Δν) -----(1)
Based on the above equation, as the changes in energy levels increase, the frequency of emitted radiation will also increase.
The answer would be 4.
The agencies are:
Department of Agriculture's Forest Service (AFS)
Department of the Interior's Bureau of Land Management (BLM)
Fish and Wildlife Service (FWS)
National Park Service (NPS)
These four agencies cover around 95% of the land and are the only federal agencies.
I learned about these agencies in school.
Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :

where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get


Therefore, the molecular weight of a substance is 157.3 g/mol