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Ahmed Nour ✓™
12/1/2025
Chemistry
Orbitals, shapes of molecule and polarity
128
•
Dec 1, 2025
•
Ahmed Nour ✓™
@ahmednour
Chemistry concepts can seem complex, but understanding the patterns of... Show more
An orbital is a region with a high probability of finding an electron, with each orbital holding up to 2 electrons. Electrons fill orbitals in increasing energy order (1s, 2s, 2p, etc.), and they prefer to occupy orbitals singly before pairing up. Remember these key exceptions: 4s fills before 3d (but empties first when writing electron configurations), and elements like chromium (3d⁵4s¹) and copper (3d¹⁰4s¹) have unusual configurations so each electron can have its own orbital.
Molecular shapes depend on the arrangement of electron pairs around the central atom. Linear molecules have a 180° bond angle with two bonding pairs and no lone pairs. Tetrahedral molecules (like CH₄) have four bonding pairs arranged at 109.5° angles. Other important shapes include non-linear (like H₂O, 104.5°), trigonal planar (like BF₃, 120°), pyramidal (like NH₃, 107.5°), and octahedral (six bonding pairs at 90° angles).
A molecule's polarity depends on both bond polarity and molecular shape. Even with polar bonds, a molecule can be non-polar if its dipole moments cancel out. For example, CO₂ has polar C-O bonds, but the linear arrangement causes the dipoles to cancel, making the molecule non-polar. NH₃, however, has dipoles that don't cancel, making it polar.
Remember this! Lone pairs repel more strongly than bonding pairs, which is why water's H-O-H angle (104.5°) is smaller than the perfect tetrahedral angle (109.5°).
Electronegativity refers to an atom's ability to attract bonding electrons in a covalent bond. This property follows predictable trends across the periodic table. Across a period (left to right), electronegativity increases as nuclear charge increases while the number of electron shells stays the same, creating stronger attraction for bonding electrons.
Down a group, electronegativity decreases despite increasing proton number. This happens because the additional electron shells create more shielding, which negates the increased nuclear charge and results in less attraction between the nucleus and bonding electrons.
Fluorine is the most electronegative element, with electronegativity generally decreasing as you move left and down the periodic table. When two atoms of the same element share electrons (like in Cl₂), they have identical electronegativity, resulting in equal electron sharing and a non-polar bond.
When atoms with different electronegativities bond , the more electronegative atom (Cl) pulls the shared electrons closer, creating a partial negative charge (δ-) on that atom and a partial positive charge (δ+) on the less electronegative atom (H). This separation of charge creates a dipole moment, resulting in a polar covalent bond.
Chemistry hack: To quickly determine if a molecule is polar, check both the electronegativity differences (are the bonds polar?) and the molecular shape (do the dipoles cancel?). Both factors matter!
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.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
App Store
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
Ahmed Nour ✓™
@ahmednour
Chemistry concepts can seem complex, but understanding the patterns of electrons and molecular shapes will help you master this subject. This summary covers orbitals, electron configurations, molecular shapes, and electronegativity—essential concepts for predicting how atoms interact.
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An orbital is a region with a high probability of finding an electron, with each orbital holding up to 2 electrons. Electrons fill orbitals in increasing energy order (1s, 2s, 2p, etc.), and they prefer to occupy orbitals singly before pairing up. Remember these key exceptions: 4s fills before 3d (but empties first when writing electron configurations), and elements like chromium (3d⁵4s¹) and copper (3d¹⁰4s¹) have unusual configurations so each electron can have its own orbital.
Molecular shapes depend on the arrangement of electron pairs around the central atom. Linear molecules have a 180° bond angle with two bonding pairs and no lone pairs. Tetrahedral molecules (like CH₄) have four bonding pairs arranged at 109.5° angles. Other important shapes include non-linear (like H₂O, 104.5°), trigonal planar (like BF₃, 120°), pyramidal (like NH₃, 107.5°), and octahedral (six bonding pairs at 90° angles).
A molecule's polarity depends on both bond polarity and molecular shape. Even with polar bonds, a molecule can be non-polar if its dipole moments cancel out. For example, CO₂ has polar C-O bonds, but the linear arrangement causes the dipoles to cancel, making the molecule non-polar. NH₃, however, has dipoles that don't cancel, making it polar.
Remember this! Lone pairs repel more strongly than bonding pairs, which is why water's H-O-H angle (104.5°) is smaller than the perfect tetrahedral angle (109.5°).
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Electronegativity refers to an atom's ability to attract bonding electrons in a covalent bond. This property follows predictable trends across the periodic table. Across a period (left to right), electronegativity increases as nuclear charge increases while the number of electron shells stays the same, creating stronger attraction for bonding electrons.
Down a group, electronegativity decreases despite increasing proton number. This happens because the additional electron shells create more shielding, which negates the increased nuclear charge and results in less attraction between the nucleus and bonding electrons.
Fluorine is the most electronegative element, with electronegativity generally decreasing as you move left and down the periodic table. When two atoms of the same element share electrons (like in Cl₂), they have identical electronegativity, resulting in equal electron sharing and a non-polar bond.
When atoms with different electronegativities bond , the more electronegative atom (Cl) pulls the shared electrons closer, creating a partial negative charge (δ-) on that atom and a partial positive charge (δ+) on the less electronegative atom (H). This separation of charge creates a dipole moment, resulting in a polar covalent bond.
Chemistry hack: To quickly determine if a molecule is polar, check both the electronegativity differences (are the bonds polar?) and the molecular shape (do the dipoles cancel?). Both factors matter!
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.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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Learn about atomic theory, identifying lab equipment, how to make Bohr models, and more.
ChemistryExplore the fundamentals of covalent bonding, including electron sharing, dot and cross diagrams, and the properties of simple covalent structures. This summary covers key concepts such as low melting and boiling points, and the lack of electrical conductivity in covalent compounds. Ideal for chemistry students seeking to understand molecular interactions.
ChemistryExplore the principles of molecular geometry through Valence Shell Electron Pair Repulsion (VSEPR) theory. This summary covers the calculation of electron pairs, the shapes of common molecules like CH4 and NH3, and the impact of bonding and non-bonding electrons on molecular structure. Ideal for chemistry students preparing for exams or seeking to understand molecular shapes in detail.
ChemistryApp Store
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
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