# Energy levels and quantum numbers

In summary, the conversation is about the topic of quantum numbers in electron structure and orbitals. The speaker is seeking help and clarification on how quantum numbers relate to electron configuration and has provided an example question from their homework. They mention that the book's explanation is unclear and ask for assistance in understanding the concept. The conversation ends with the speaker expressing gratitude for any help provided.

Hey guys, this isn't really homework but will help me on the exam and the homework too. We are working in the book, where you just get to electron structure, orbitals, configurations, etc.

The part that I need help with is Quantum Numbers. My book has:
n(principal energy levels)
l(sublevels)
ml(Orbitals)
ms(Electron Spin)

I don't really understand this part, the book explains it very poorly. I understand Electron configuration(1s2s,2p,etc). If someone could help me relate this information, I'd be very grateful. I'm not sure how it all ties together.

Here is an example question(homework) that I don't understand completely.

How many electrons in an atom can have each of the following quantum number designations?
a. n=1, l=0, ml=0
b. n = 5, l=3, ml=+2
c. n=3, l=2

Thank you,

Anyone know this stuff, I know its basic...but any help would be great!

Much better explanation, thank you Geoffjb...I appreciate it!

## What are energy levels in an atom?

Energy levels in an atom refer to the fixed and specific amounts of energy that an electron can have within an atom. These energy levels are represented by quantum numbers and serve as the basis for understanding the behavior of electrons in an atom.

## What are quantum numbers?

Quantum numbers are a set of four numbers that describe the energy, position, and orientation of an electron in an atom. The principal quantum number (n) determines the energy level, the angular momentum quantum number (l) determines the shape of the orbital, the magnetic quantum number (ml) determines the orientation of the orbital, and the spin quantum number (ms) determines the direction of the electron's spin.

## What is the relationship between energy levels and quantum numbers?

Each energy level in an atom is represented by a different principal quantum number (n). This means that as the energy level increases, the principal quantum number also increases. Additionally, the other quantum numbers (l, ml, ms) also change with each energy level, allowing for a more detailed description of an electron's properties within an atom.

## How are energy levels and quantum numbers related to the periodic table?

The periodic table is organized based on the number of protons in an atom's nucleus, also known as the atomic number. The atomic number determines the number of electrons in an atom, which in turn determines the energy levels and quantum numbers for those electrons. This is why elements with the same number of electrons in their outermost energy level (valence electrons) exhibit similar chemical properties.

## Can energy levels and quantum numbers change?

Yes, energy levels and quantum numbers can change when an electron gains or loses energy. This can happen through absorption or emission of photons, which are packets of energy. When this occurs, the electron can jump to a higher or lower energy level, resulting in a change of quantum numbers. This is the basis for phenomena such as atomic emission spectra and the behavior of electrons in chemical reactions.