Subjects
Careers
Biology
Geometry
English
AP English Literature
Fun Stuff
104
0
Keara Fish
9/21/2025
Chemistry
Atoms and Isotopes
211
•
Sep 21, 2025
•
Keara Fish
@kearafish4
John Dalton's atomic theoryrevolutionized our understanding of matter at... Show more
This page delves deeper into the properties and structure of subatomic particles, providing a detailed table comparing their relative masses and charges. It also introduces the concept of isotopes and explains the structure of the nucleus and electron orbitals.
Isotopes are defined as species of an element with the same atomic number and chemical behavior but different atomic masses due to varying numbers of neutrons. The page emphasizes the importance of the nucleus as the tiny central core of an atom composed of protons and neutrons.
The atomic number and mass number are introduced as key concepts for distinguishing between atoms:
Example: The atomic symbol for hydrogen (¹H) shows its atomic number (1) and mass number (1).
Definition: Isotopes are atoms of the same element with different numbers of neutrons but the same number of protons.
Highlight: The number of neutrons in an atom can be calculated by subtracting the atomic number from the mass number.
This page provides a comprehensive table of the first 10 elements in the periodic table, listing their names, symbols, atomic numbers, and the number of protons, neutrons, and electrons in their most common isotopes. This information is crucial for understanding the properties and structure of subatomic particles in different elements.
The concept of natural abundance and isotopes of elements is introduced with a table showing the relative abundance of stable isotopes for common elements like hydrogen, carbon, nitrogen, and oxygen. This information is vital for understanding isotopic composition in nature and its applications in various scientific fields.
Example: Carbon has two main stable isotopes: Carbon-12 and Carbon-13 (1.11% abundance).
Highlight: The natural abundance of isotopes can vary slightly in different environments, which is useful for tracing the origin of materials in geology and environmental science.
Vocabulary: Natural abundance refers to the relative proportion of different isotopes of an element as they occur in nature.
This page introduces John Dalton's atomic theory and the basic structure of atoms. Dalton proposed that all elements are composed of tiny, indivisible particles called atoms. He stated that atoms of the same element are identical, while atoms of different elements have distinct properties. According to Dalton, chemical reactions occur when atoms are separated, joined, or rearranged, but atoms themselves are not changed into other elements during reactions.
The modern definition of an atom is provided as the smallest particle of an element that retains its identity in a chemical reaction. The page then describes the structure of the nuclear atom, introducing the three main subatomic particles:
Definition: An atom is the smallest particle of an element that retains its identity in a chemical reaction.
Highlight: The nucleus contains protons and neutrons, while electrons orbit around it in energy levels called shells.
Vocabulary: Valence electrons are the outermost electrons of an atom, which are involved in chemical bonding.
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
Keara Fish
@kearafish4
John Dalton's atomic theory revolutionized our understanding of matter at the atomic level. This summary explores key concepts including the structure of atoms, subatomic particles, isotopes, and natural abundance.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This page delves deeper into the properties and structure of subatomic particles, providing a detailed table comparing their relative masses and charges. It also introduces the concept of isotopes and explains the structure of the nucleus and electron orbitals.
Isotopes are defined as species of an element with the same atomic number and chemical behavior but different atomic masses due to varying numbers of neutrons. The page emphasizes the importance of the nucleus as the tiny central core of an atom composed of protons and neutrons.
The atomic number and mass number are introduced as key concepts for distinguishing between atoms:
Example: The atomic symbol for hydrogen (¹H) shows its atomic number (1) and mass number (1).
Definition: Isotopes are atoms of the same element with different numbers of neutrons but the same number of protons.
Highlight: The number of neutrons in an atom can be calculated by subtracting the atomic number from the mass number.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This page provides a comprehensive table of the first 10 elements in the periodic table, listing their names, symbols, atomic numbers, and the number of protons, neutrons, and electrons in their most common isotopes. This information is crucial for understanding the properties and structure of subatomic particles in different elements.
The concept of natural abundance and isotopes of elements is introduced with a table showing the relative abundance of stable isotopes for common elements like hydrogen, carbon, nitrogen, and oxygen. This information is vital for understanding isotopic composition in nature and its applications in various scientific fields.
Example: Carbon has two main stable isotopes: Carbon-12 and Carbon-13 (1.11% abundance).
Highlight: The natural abundance of isotopes can vary slightly in different environments, which is useful for tracing the origin of materials in geology and environmental science.
Vocabulary: Natural abundance refers to the relative proportion of different isotopes of an element as they occur in nature.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This page introduces John Dalton's atomic theory and the basic structure of atoms. Dalton proposed that all elements are composed of tiny, indivisible particles called atoms. He stated that atoms of the same element are identical, while atoms of different elements have distinct properties. According to Dalton, chemical reactions occur when atoms are separated, joined, or rearranged, but atoms themselves are not changed into other elements during reactions.
The modern definition of an atom is provided as the smallest particle of an element that retains its identity in a chemical reaction. The page then describes the structure of the nuclear atom, introducing the three main subatomic particles:
Definition: An atom is the smallest particle of an element that retains its identity in a chemical reaction.
Highlight: The nucleus contains protons and neutrons, while electrons orbit around it in energy levels called shells.
Vocabulary: Valence electrons are the outermost electrons of an atom, which are involved in chemical bonding.
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.
104
Hol dir die App, um Zugang zu den smarten Tools mit interaktiven Karteikarten, Übungsaufgaben, Probeklausuren und Zusammenfassungen zu bekommen
What are significant figures, and how to use them?
ChemistryDiscussed here are the different theories such as Dalton’s Atomic Theory, Thomson’s Model – Plum Pudding, Rutherford’s Model, Bohr’s Model – Planetary, Quantum Mechanical Model.
ChemistryThis involves fundamental concepts in chemistry, periodic table, analysis of simple experimental set-ups, laws and principles.
ChemistryExplore the concept of isotopes, including their definitions, similarities, and differences. This summary covers key aspects such as the number of protons and neutrons, chemical properties, and examples of isotopes for elements like carbon, hydrogen, and chlorine. Ideal for students preparing for exams or seeking to deepen their understanding of atomic structure.
ChemistryExplore the concepts of isotopes and relative atomic mass in this detailed summary. Learn how to calculate the average atomic mass using isotope abundance and mass, with a focus on practical examples like Copper. Ideal for chemistry students preparing for exams.
Chemistrydifferent electron configurations for chemistry; examples included
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
