Biology
Chemistry
AP Chemistry
English
AP English Literature
196
•
Dec 28, 2025
•
Gabriella
@gabsgabaga
Understanding atomic structure and chemical bonding is absolutely crucial for... Show more
Ever wondered what makes gold different from oxygen? It's all about atomic structure and how particles are arranged. An element contains only one type of atom (like pure gold), whilst a compound has different types of atoms chemically stuck together (like water, H₂O).
Mixtures are completely different - they're just different substances mixed together without any chemical bonding happening. Think of it like a fruit salad where each piece of fruit keeps its own identity.
There's a handy naming trick for compounds: if there are only two elements, the name ends in 'ide' (like copper oxide). With three elements, it usually ends in 'ate' (like barium carbonate). The exception is compounds with 'OH' - these are always called hydroxides.
Quick Tip: Remember that protons and neutrons have roughly the same mass , but electrons are tiny - about 2000 times lighter!
The numbers on the periodic table tell you everything about an atom's structure. The mass number (big number) equals protons plus neutrons, whilst the atomic number (small number) tells you how many protons are there.
Here's the key relationship: number of electrons always equals number of protons in neutral atoms. To find neutrons, simply subtract the atomic number from the mass number.
Isotopes are atoms of the same element with different numbers of neutrons - like two versions of the same person wearing different shoes. Chlorine has isotopes with either 18 or 20 neutrons, but both still have 17 protons.
Electron shells work like energy levels around the nucleus. Electrons fill up the closest shell first (maximum 2), then the second shell (maximum 8), and so on. The number of outer electrons matches the group number on the periodic table, whilst the number of shells matches the period number.
Remember: Noble gases have full outer shells, which is why they're so unreactive - they're already 'happy'!
Atoms bond together because they want full outer shells like the noble gases. There are two main types: ionic bonding and covalent bonding .
In ionic bonding, electrons transfer completely from metal to non-metal atoms. Metals lose electrons and become positive ions, whilst non-metals gain electrons and become negative ions. Think of sodium chloride: sodium gives up one electron to become Na⁺, and chlorine accepts it to become Cl⁻.
These oppositely charged ions attract each other through electrostatic forces, creating a giant lattice structure. This isn't just a few ions stuck together - it's a massive, regular pattern that continues in all directions throughout the entire crystal.
Scientific models help us visualise these complex structures in simpler ways, showing the key features without overwhelming detail.
Key Point: Metals always form positive ions, non-metals always form negative ions - opposites attract!
Ionic compounds have distinctive properties that all stem from their giant lattice structure and the strong forces holding ions together. They have high melting points because you need loads of energy to break those strong electrostatic attractions between ions.
Water can dissolve many ionic compounds because the charged ions attract water molecules and form weak bonds with them. The ions basically get surrounded by water molecules and pulled away from the lattice.
Electrical conductivity depends on whether ions can move. In solid form, ionic compounds don't conduct electricity because ions are locked in fixed positions. However, when molten or dissolved, the ions become free to move and can carry electrical current between electrodes.
Ionic compounds are brittle - they shatter rather than bend. When you try to change their shape, you end up pushing ions with the same charge next to each other, and they repel strongly enough to break the structure apart.
Remember: Free-moving ions = electrical conduction. Fixed ions = no conduction.
Metallic bonding creates a completely different structure called a giant metallic lattice. Picture positive metal ions surrounded by a 'sea' of delocalised electrons that are free to move throughout the entire structure.
These mobile electrons explain why metals are such good electrical and thermal conductors - the electrons can move freely and carry charge or energy. The strong metallic bonds also give metals high melting and boiling points.
Unlike ionic compounds, metals are malleable (can be hammered into shapes) and ductile (can be drawn into wires). This happens because layers of atoms can slide over each other whilst maintaining the metallic bonding - the electron sea just flows around the moving atoms.
Scientists use different models to represent these structures, from simple 'ball and stick' diagrams to more realistic 'space-filling' representations that show how tightly packed atoms really are.
Fun Fact: The same delocalised electrons that let metals conduct electricity also make them shiny - they reflect light really well!
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
Gabriella
@gabsgabaga
Understanding atomic structure and chemical bonding is absolutely crucial for mastering GCSE chemistry. This topic covers everything from the basic building blocks of matter to how atoms stick together to form compounds - knowledge you'll use in every other chemistry... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wondered what makes gold different from oxygen? It's all about atomic structure and how particles are arranged. An element contains only one type of atom (like pure gold), whilst a compound has different types of atoms chemically stuck together (like water, H₂O).
Mixtures are completely different - they're just different substances mixed together without any chemical bonding happening. Think of it like a fruit salad where each piece of fruit keeps its own identity.
There's a handy naming trick for compounds: if there are only two elements, the name ends in 'ide' (like copper oxide). With three elements, it usually ends in 'ate' (like barium carbonate). The exception is compounds with 'OH' - these are always called hydroxides.
Quick Tip: Remember that protons and neutrons have roughly the same mass , but electrons are tiny - about 2000 times lighter!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The numbers on the periodic table tell you everything about an atom's structure. The mass number (big number) equals protons plus neutrons, whilst the atomic number (small number) tells you how many protons are there.
Here's the key relationship: number of electrons always equals number of protons in neutral atoms. To find neutrons, simply subtract the atomic number from the mass number.
Isotopes are atoms of the same element with different numbers of neutrons - like two versions of the same person wearing different shoes. Chlorine has isotopes with either 18 or 20 neutrons, but both still have 17 protons.
Electron shells work like energy levels around the nucleus. Electrons fill up the closest shell first (maximum 2), then the second shell (maximum 8), and so on. The number of outer electrons matches the group number on the periodic table, whilst the number of shells matches the period number.
Remember: Noble gases have full outer shells, which is why they're so unreactive - they're already 'happy'!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Atoms bond together because they want full outer shells like the noble gases. There are two main types: ionic bonding and covalent bonding .
In ionic bonding, electrons transfer completely from metal to non-metal atoms. Metals lose electrons and become positive ions, whilst non-metals gain electrons and become negative ions. Think of sodium chloride: sodium gives up one electron to become Na⁺, and chlorine accepts it to become Cl⁻.
These oppositely charged ions attract each other through electrostatic forces, creating a giant lattice structure. This isn't just a few ions stuck together - it's a massive, regular pattern that continues in all directions throughout the entire crystal.
Scientific models help us visualise these complex structures in simpler ways, showing the key features without overwhelming detail.
Key Point: Metals always form positive ions, non-metals always form negative ions - opposites attract!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ionic compounds have distinctive properties that all stem from their giant lattice structure and the strong forces holding ions together. They have high melting points because you need loads of energy to break those strong electrostatic attractions between ions.
Water can dissolve many ionic compounds because the charged ions attract water molecules and form weak bonds with them. The ions basically get surrounded by water molecules and pulled away from the lattice.
Electrical conductivity depends on whether ions can move. In solid form, ionic compounds don't conduct electricity because ions are locked in fixed positions. However, when molten or dissolved, the ions become free to move and can carry electrical current between electrodes.
Ionic compounds are brittle - they shatter rather than bend. When you try to change their shape, you end up pushing ions with the same charge next to each other, and they repel strongly enough to break the structure apart.
Remember: Free-moving ions = electrical conduction. Fixed ions = no conduction.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Metallic bonding creates a completely different structure called a giant metallic lattice. Picture positive metal ions surrounded by a 'sea' of delocalised electrons that are free to move throughout the entire structure.
These mobile electrons explain why metals are such good electrical and thermal conductors - the electrons can move freely and carry charge or energy. The strong metallic bonds also give metals high melting and boiling points.
Unlike ionic compounds, metals are malleable (can be hammered into shapes) and ductile (can be drawn into wires). This happens because layers of atoms can slide over each other whilst maintaining the metallic bonding - the electron sea just flows around the moving atoms.
Scientists use different models to represent these structures, from simple 'ball and stick' diagrams to more realistic 'space-filling' representations that show how tightly packed atoms really are.
Fun Fact: The same delocalised electrons that let metals conduct electricity also make them shiny - they reflect light really well!
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.
46
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
chemistry
ChemistrySteps in naming metallic and non-metallic ions.
ChemistryExplore the fundamental concepts of ionic bonding, including the structure of ionic compounds, their properties, and the process of electron transfer between metals and nonmetals. This summary includes a dot and cross diagram example for visual understanding, making it ideal for exam preparation.
ChemistryChemistry, Atoms, Molecules, and Ions
ChemistryStudy of matter, physical states of matter, properties of matter, changes in matter, pure substance and mixtures, elements and compounds, Atoms and molecules, chemical formulas, chemical symbols, names, discovery and abundance of elements,
ChemistryExplore the fundamentals of chemical bonding, including ionic, covalent, and metallic bonds. Understand the properties of giant covalent structures and the unique allotropes of carbon, such as diamond and graphite. This summary provides essential insights for students studying chemistry.
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
Biology
Sociology