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Dec 9, 2025
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Ever wonder how chemists keep track of thousands of compounds without getting confused? It's all about naming rules!... Show more
Ions are atoms or groups of atoms with electrical charges. Knowing how to name them is your first step to naming compounds.
Cations (positively charged ions) are typically named by adding the word "ion" after the element name. For example, Na becomes sodium ion (Na⁺) and Al becomes aluminum ion (Al³⁺). When dealing with transition metals that form multiple ions with different charges, we add Roman numerals in parentheses after the name, like copper(I) ion (Cu⁺) and copper(II) ion (Cu²⁺).
Anions (negatively charged ions) from single elements take the element's name but change the ending to "-ide." For example, Cl becomes chloride ion (Cl⁻) and S becomes sulfide ion (S²⁻). Polyatomic anions containing oxygen typically end in "-ite" or "-ate," with "-ate" being more common.
💡 Quick Tip Think of "-ide" as the ending for simple anions, while "-ate" and "-ite" indicate oxygen-containing polyatomic ions. The "-ate" ending usually indicates more oxygen atoms than the "-ite" version.
Polyatomic ions are charged particles made up of multiple atoms. You'll see these everywhere in chemistry, so it's worth getting to know them.
When an element forms multiple oxyanions , there's a pattern to the naming. If there are two oxyanions with the same charge, the one with fewer oxygens ends in "-ite" while the one with more oxygens ends in "-ate." For elements forming four oxyanions (like chlorine), we add prefixes "hypo-" (least oxygen) and "per-" (most oxygen) to create a sequence hypochlorite → chlorite → chlorate → perchlorate.
Some oxyanions can gain hydrogen atoms to form new ions. We name these by adding "hydrogen" or "dihydrogen" before the original ion name. For example, carbonate (CO₃²⁻) becomes hydrogen carbonate (HCO₃⁻), and phosphate (PO₄³⁻) can form both hydrogen phosphate (HPO₄²⁻) and dihydrogen phosphate (H₂PO₄⁻).
Common oxyanions you should memorize include acetate (CH₃CO₂⁻), carbonate (CO₃²⁻), nitrate (NO₃⁻), sulfate (SO₄²⁻), and hydroxide (OH⁻). These appear frequently in chemistry problems and lab work.
💡 Memory Aid The more oxygen atoms, the "greater" the name -ite → -ate. And if there are four variations, think "hypo" (below) to "per" (above) as a spectrum from least to most oxygen.
Now that you know how to name ions, naming ionic compounds is straightforward just put the cation name first, followed by the anion name.
For binary ionic compounds (containing just two elements), simply combine the names. For example, K₂S is potassium sulfide, and FeBr₃ is iron(III) bromide. Remember to include the Roman numeral for transition metals that form multiple ions.
Compounds with polyatomic ions follow the same pattern. Examples include ammonium chloride (NH₄Cl), potassium sulfate (K₂SO₄), and copper(II) carbonate (CuCO₃). Even when there are multiple polyatomic ions, like in Mg₃(PO₄)₂ (magnesium phosphate), the naming rule remains the same.
Some ionic compounds include water molecules in their crystal structure. These hydrates are named by adding the word "hydrate" with a prefix indicating the number of water molecules. For instance, CuSO₄·5H₂O is copper(II) sulfate pentahydrate . Other common prefixes include di- (2), tri- (3), tetra- (4), and octa- (8).
💡 Real-world Connection Hydrates are everywhere! That blue copper sulfate pentahydrate in your chemistry lab is also used in swimming pools to control algae growth, while magnesium sulfate heptahydrate is the Epsom salt you might use in a relaxing bath.
Acids and molecular compounds follow their own naming patterns that are different from ionic compounds.
Acids can be thought of as hydrogen ions (H⁺) bonded to anions. For acids with oxyanions, change the "-ate" ending to "-ic acid" and the "-ite" ending to "-ous acid." For example, nitrate (NO₃⁻) becomes nitric acid (HNO₃), while nitrite (NO₂⁻) becomes nitrous acid (HNO₂). If dealing with "hypo-" or "per-" oxyanions, these prefixes stay the same in the acid name.
Binary molecular compounds use prefixes to show the number of each atom. The element farther left in the periodic table usually comes first (except oxygen, which usually goes last unless paired with fluorine). The second element gets an "-ide" ending. For instance, CO₂ is carbon dioxide, and N₂O₄ is dinitrogen tetroxide.
Some common molecular compounds have traditional names that don't follow these rules, like water (H₂O), ammonia (NH₃), and methane (CH₄). You'll need to memorize these exceptions.
💡 Test Tip When naming acids, remember "-ate" becomes "-ic" and "-ite" becomes "-ous." For example, sulfate → sulfuric acid, and sulfite → sulfurous acid. This pattern appears frequently on chemistry exams!
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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Explore the properties of ionic compounds, including their structure, high melting and boiling points, and electrical conductivity in different states. This summary covers key concepts such as ionic bonding, giant ionic lattices, and the behavior of ions in solid and liquid forms.
ChemistryExplore the fundamental concepts of chemical bonding, including covalent, ionic, and metallic bonds, as well as the properties of solids, liquids, and gases. This summary covers key topics such as carbon allotropes, giant covalent structures, and the particle theory, providing a comprehensive overview for chemistry revision.
BiologyHow do we know that the compound is an ionic compound?
ChemistryThis contains the rules in naming amine and amides.
ChemistryHandwritten notes based on the information in Unit 7: Chemical Nomenclature from CK-12 Chemistry for High School
ChemistryChapter 9
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
Ever wonder how chemists keep track of thousands of compounds without getting confused? It's all about naming rules! Chemical nomenclature is like a universal language that tells you exactly what's in a compound just from its name. Mastering these patterns... Show more
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Ions are atoms or groups of atoms with electrical charges. Knowing how to name them is your first step to naming compounds.
Cations (positively charged ions) are typically named by adding the word "ion" after the element name. For example, Na becomes sodium ion (Na⁺) and Al becomes aluminum ion (Al³⁺). When dealing with transition metals that form multiple ions with different charges, we add Roman numerals in parentheses after the name, like copper(I) ion (Cu⁺) and copper(II) ion (Cu²⁺).
Anions (negatively charged ions) from single elements take the element's name but change the ending to "-ide." For example, Cl becomes chloride ion (Cl⁻) and S becomes sulfide ion (S²⁻). Polyatomic anions containing oxygen typically end in "-ite" or "-ate," with "-ate" being more common.
💡 Quick Tip: Think of "-ide" as the ending for simple anions, while "-ate" and "-ite" indicate oxygen-containing polyatomic ions. The "-ate" ending usually indicates more oxygen atoms than the "-ite" version.
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Polyatomic ions are charged particles made up of multiple atoms. You'll see these everywhere in chemistry, so it's worth getting to know them.
When an element forms multiple oxyanions , there's a pattern to the naming. If there are two oxyanions with the same charge, the one with fewer oxygens ends in "-ite" while the one with more oxygens ends in "-ate." For elements forming four oxyanions (like chlorine), we add prefixes "hypo-" (least oxygen) and "per-" (most oxygen) to create a sequence: hypochlorite → chlorite → chlorate → perchlorate.
Some oxyanions can gain hydrogen atoms to form new ions. We name these by adding "hydrogen" or "dihydrogen" before the original ion name. For example, carbonate (CO₃²⁻) becomes hydrogen carbonate (HCO₃⁻), and phosphate (PO₄³⁻) can form both hydrogen phosphate (HPO₄²⁻) and dihydrogen phosphate (H₂PO₄⁻).
Common oxyanions you should memorize include acetate (CH₃CO₂⁻), carbonate (CO₃²⁻), nitrate (NO₃⁻), sulfate (SO₄²⁻), and hydroxide (OH⁻). These appear frequently in chemistry problems and lab work.
💡 Memory Aid: The more oxygen atoms, the "greater" the name: -ite → -ate. And if there are four variations, think "hypo" (below) to "per" (above) as a spectrum from least to most oxygen.
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Now that you know how to name ions, naming ionic compounds is straightforward: just put the cation name first, followed by the anion name.
For binary ionic compounds (containing just two elements), simply combine the names. For example, K₂S is potassium sulfide, and FeBr₃ is iron(III) bromide. Remember to include the Roman numeral for transition metals that form multiple ions.
Compounds with polyatomic ions follow the same pattern. Examples include ammonium chloride (NH₄Cl), potassium sulfate (K₂SO₄), and copper(II) carbonate (CuCO₃). Even when there are multiple polyatomic ions, like in Mg₃(PO₄)₂ (magnesium phosphate), the naming rule remains the same.
Some ionic compounds include water molecules in their crystal structure. These hydrates are named by adding the word "hydrate" with a prefix indicating the number of water molecules. For instance, CuSO₄·5H₂O is copper(II) sulfate pentahydrate . Other common prefixes include di- (2), tri- (3), tetra- (4), and octa- (8).
💡 Real-world Connection: Hydrates are everywhere! That blue copper sulfate pentahydrate in your chemistry lab is also used in swimming pools to control algae growth, while magnesium sulfate heptahydrate is the Epsom salt you might use in a relaxing bath.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Acids and molecular compounds follow their own naming patterns that are different from ionic compounds.
Acids can be thought of as hydrogen ions (H⁺) bonded to anions. For acids with oxyanions, change the "-ate" ending to "-ic acid" and the "-ite" ending to "-ous acid." For example, nitrate (NO₃⁻) becomes nitric acid (HNO₃), while nitrite (NO₂⁻) becomes nitrous acid (HNO₂). If dealing with "hypo-" or "per-" oxyanions, these prefixes stay the same in the acid name.
Binary molecular compounds use prefixes to show the number of each atom. The element farther left in the periodic table usually comes first (except oxygen, which usually goes last unless paired with fluorine). The second element gets an "-ide" ending. For instance, CO₂ is carbon dioxide, and N₂O₄ is dinitrogen tetroxide.
Some common molecular compounds have traditional names that don't follow these rules, like water (H₂O), ammonia (NH₃), and methane (CH₄). You'll need to memorize these exceptions.
💡 Test Tip: When naming acids, remember: "-ate" becomes "-ic" and "-ite" becomes "-ous." For example, sulfate → sulfuric acid, and sulfite → sulfurous acid. This pattern appears frequently on chemistry exams!
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.
8
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the properties of ionic compounds, including their structure, high melting and boiling points, and electrical conductivity in different states. This summary covers key concepts such as ionic bonding, giant ionic lattices, and the behavior of ions in solid and liquid forms.
ChemistryExplore the fundamental concepts of chemical bonding, including covalent, ionic, and metallic bonds, as well as the properties of solids, liquids, and gases. This summary covers key topics such as carbon allotropes, giant covalent structures, and the particle theory, providing a comprehensive overview for chemistry revision.
BiologyHow do we know that the compound is an ionic compound?
ChemistryThis contains the rules in naming amine and amides.
ChemistryHandwritten notes based on the information in Unit 7: Chemical Nomenclature from CK-12 Chemistry for High School
ChemistryChapter 9
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
Algebra
Calculus 1
Algebra 1
Overige