Dive into the quantum model of the atom where electrons... Show more
Algebra
Calculus 1
Algebra 1
OverigeSign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
5
0
Maria Hernandez
12/4/2025
Chemistry
The Quantum Model
75
•
Dec 4, 2025
•
Understanding the Quantum Model and Its Four Important Numbers
Maria Hernandez
@mariahernandez
The Quantum Model of the Atom
Ever wondered why electrons don't simply crash into the nucleus? The quantum model explains this mystery! In 1924, de Broglie discovered that electrons exhibit both particle and wave properties, changing our understanding of atomic structure forever.
The Heisenberg Uncertainty Principle (1927) adds another layer of complexity - it states that we can never simultaneously know both an electron's position and velocity. This isn't just a limitation of our measuring tools; it's a fundamental property of nature!
Schrödinger's equation (1926) treats electrons as waves, giving us probability maps called wave functions that show where electrons are likely to be found around the nucleus. Instead of fixed paths, electrons exist in orbitals - three-dimensional spaces with different shapes.
💡 Quick Tip: Think of orbitals not as paths but as "electron neighborhoods" - areas where electrons are likely to be found. The denser the area in models, the higher the probability of finding electrons there!
The four quantum numbers describe electrons in these orbitals:
- Principal Quantum Number (n): Identifies the energy level (1, 2, 3...)
- Angular Momentum Quantum Number (l): Determines orbital shape (s, p, d, f)
- Magnetic Quantum Number (m): Shows orbital orientation in space
- Spin Quantum Number (s): Either +½ or -½
Different orbital shapes include spherical s-orbitals (1 per sublevel), dumbbell-shaped p-orbitals (3 per sublevel), cloverleaf-like d-orbitals (5 per sublevel), and complex f-orbitals (7 per sublevel). Remember, each orbital can hold a maximum of 2 electrons!
Electron Configuration and the Aufbau Principle
Electrons fill orbitals in a specific order, following what's called the Aufbau Principle (German for "building up"). This principle helps us predict how electrons arrange themselves in atoms of different elements.
Each energy level (or shell) contains different types of sublevels (s, p, d, f), and each sublevel contains different numbers of orbitals. The s-sublevel contains 1 orbital (maximum 2 electrons), the p-sublevel has 3 orbitals (maximum 6 electrons), the d-sublevel has 5 orbitals (maximum 10 electrons), and the f-sublevel has 7 orbitals (maximum 14 electrons).
Looking at the Aufbau diagram, electrons fill from bottom to top, starting with 1s, then 2s, 2p, and so on. The diagram shows that the 4th shell can have s, p, d, and f sublevels, while the 1st shell only has an s sublevel. This pattern explains the periodic table's structure!
⚠️ Watch Out! Energy levels don't always fill in perfect numerical order. For example, the 4s orbital fills before the 3d orbital because of their relative energy levels. This is why the periodic table has its characteristic shape!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content: Quantum Numbers
Most popular content in AP Chemistry
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
Understanding the Quantum Model and Its Four Important Numbers
Maria Hernandez
@mariahernandez
Dive into the quantum model of the atom where electrons don't follow neat paths but exist in probability clouds! This fascinating concept revolutionized how scientists understand atomic structure, replacing the simple planetary model with a complex system described by quantum... Show more
The Quantum Model of the Atom
Ever wondered why electrons don't simply crash into the nucleus? The quantum model explains this mystery! In 1924, de Broglie discovered that electrons exhibit both particle and wave properties, changing our understanding of atomic structure forever.
The Heisenberg Uncertainty Principle (1927) adds another layer of complexity - it states that we can never simultaneously know both an electron's position and velocity. This isn't just a limitation of our measuring tools; it's a fundamental property of nature!
Schrödinger's equation (1926) treats electrons as waves, giving us probability maps called wave functions that show where electrons are likely to be found around the nucleus. Instead of fixed paths, electrons exist in orbitals - three-dimensional spaces with different shapes.
💡 Quick Tip: Think of orbitals not as paths but as "electron neighborhoods" - areas where electrons are likely to be found. The denser the area in models, the higher the probability of finding electrons there!
The four quantum numbers describe electrons in these orbitals:
- Principal Quantum Number (n): Identifies the energy level (1, 2, 3...)
- Angular Momentum Quantum Number (l): Determines orbital shape (s, p, d, f)
- Magnetic Quantum Number (m): Shows orbital orientation in space
- Spin Quantum Number (s): Either +½ or -½
Different orbital shapes include spherical s-orbitals (1 per sublevel), dumbbell-shaped p-orbitals (3 per sublevel), cloverleaf-like d-orbitals (5 per sublevel), and complex f-orbitals (7 per sublevel). Remember, each orbital can hold a maximum of 2 electrons!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Electron Configuration and the Aufbau Principle
Electrons fill orbitals in a specific order, following what's called the Aufbau Principle (German for "building up"). This principle helps us predict how electrons arrange themselves in atoms of different elements.
Each energy level (or shell) contains different types of sublevels (s, p, d, f), and each sublevel contains different numbers of orbitals. The s-sublevel contains 1 orbital (maximum 2 electrons), the p-sublevel has 3 orbitals (maximum 6 electrons), the d-sublevel has 5 orbitals (maximum 10 electrons), and the f-sublevel has 7 orbitals (maximum 14 electrons).
Looking at the Aufbau diagram, electrons fill from bottom to top, starting with 1s, then 2s, 2p, and so on. The diagram shows that the 4th shell can have s, p, d, and f sublevels, while the 1st shell only has an s sublevel. This pattern explains the periodic table's structure!
⚠️ Watch Out! Energy levels don't always fill in perfect numerical order. For example, the 4s orbital fills before the 3d orbital because of their relative energy levels. This is why the periodic table has its characteristic shape!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
5
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Similar Content
Nuclear Chem
Chemistry10th
Ionization Energy Explained
Explore the factors influencing ionization energy, including trends across periods and down groups in the periodic table. This summary covers atomic structure, electron configurations, isotopes, and mass spectrometry, providing a comprehensive understanding of how atomic properties affect ionization. Ideal for students studying chemistry concepts related to atomic structure and periodic trends.
Chemistry12
Atoms
It’s talks about the creators of each atom and what they ere made for.
AP ChemistryModern Atomic Theory
Notes about the modern atomic theory and what it means
ChemistryChemistry Scientists and their Contributions
This lists the different chemistry scientists and their contributions.
Chemistry10th
Electronic Structure of Atoms outline
outline and notes of Chapter 6: Electronic Structure of Atoms from Chemistry the Central science
Chemistry10th
Most popular content: Quantum Numbers
Most popular content in AP Chemistry
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user