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Jan 4, 2026
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Annelise
@annelise_mxtd
Chemistry is all about understanding matter, its properties, and how... Show more





Matter exists in three main states with distinct properties. Solids have definite shape and volume with particles arranged closely together. Liquids take the shape of their container while maintaining definite volume. Gases not only take their container's shape but fill the entire volume, with particles moving rapidly and far apart from each other.
The metric system provides standardized units for scientific measurements. For length, we use meters (m); for volume, liters (L); for mass, grams (g); and for temperature, either Celsius (°C) or kelvin (K). Time is measured in seconds (s) across both metric and SI systems.
Scientific notation allows us to express very large or small numbers efficiently. To convert a number to scientific notation, move the decimal point until you have a coefficient between 1 and 10, then note how many places you moved as the power of 10. Moving left gives a positive exponent (for large numbers), while moving right gives a negative exponent (for small numbers).
💡 Quick Tip: When converting between measurement systems, memorize key relationships like 1 inch = 2.54 cm and 1 kg = 2.20 lb. These conversions will appear repeatedly throughout chemistry and physics problems!

Metric prefixes help us express quantities that are much larger or smaller than the base unit. The prefixes range from femto (10⁻¹⁵) to peta (10¹⁵), with familiar ones including kilo (10³), milli (10⁻³), and micro (10⁻⁶). When you see 5.9 μL, it means 5.9 × 10⁻⁶ L.
Conversion factors are ratios that allow you to change from one unit to another while maintaining the same physical quantity. They're based on equalities—relationships that show two different ways of expressing the same amount. For example, since 1000 m = 1 km, we can write conversion factors as either or .
Real-world measurements often come with conversion factors built in. When a car travels at 65 km/hr, this tells you that 65 km equals 1 hour of travel time. Similarly, a 500 mg vitamin tablet means that 1 tablet contains 500 mg of the vitamin.
🔑 Remember: Always set up conversion factors so that your original units cancel out, leaving you with the desired units. This dimensional analysis approach helps prevent calculation errors!

Converting between units is a critical skill in chemistry. The process involves multiplying your initial measurement by the appropriate conversion factor, which is set up so that the original units cancel out. For example, to convert 5.0 hours to minutes, multiply by the factor to get 300 minutes.
Density is a fundamental property that relates the mass of a substance to its volume. It's calculated using the formula Density = mass/volume, typically measured in g/cm³ or g/mL for solids and liquids, and g/L for gases. This property is unique to each substance and helps identify unknown materials.
Density values provide useful equalities for calculations. For instance, knowing that lead has a density of 11.3 g/mL means that 11.3 g of lead equals 1 mL in volume. These relationships can be converted to fraction form and used as conversion factors in problem-solving.
🧪 Apply It: You can use density to find either mass or volume when the other is known. If you know a gold ring has a volume of 0.5 cm³ and gold's density is 19.3 g/cm³, you can calculate that the ring's mass is 9.65 g.

Density calculations allow you to find the volume of a substance when you know its mass, or vice versa. The key is to treat density as a conversion factor between mass and volume. For example, if lead has a density of 11.3 g/mL, you can write this as the conversion factor 1 mL/11.3 g lead.
To solve a density problem, first identify what you know and what you need to find. Next, determine which conversion factors you'll need, including the density. Then set up your calculation so that the units cancel properly, leaving you with the unit you want in your answer.
In the example of finding the volume of a 23-gram sample of lead, you would multiply the mass (23 g) by the conversion factor to get approximately 2.0 mL. Notice how the grams cancel out, leaving you with the volume unit (mL) that you wanted.
📐 Pro Tip: When working with density problems, always check that your final answer makes physical sense. If you're calculating the volume of a heavy metal like lead, expect a small volume for a given mass because dense materials pack a lot of mass into a small space.
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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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
Annelise
@annelise_mxtd
Chemistry is all about understanding matter, its properties, and how to measure it accurately. This chapter covers the fundamental concepts of states of matter, measurement units, scientific notation, and density calculations—skills you'll use throughout your science courses.

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Matter exists in three main states with distinct properties. Solids have definite shape and volume with particles arranged closely together. Liquids take the shape of their container while maintaining definite volume. Gases not only take their container's shape but fill the entire volume, with particles moving rapidly and far apart from each other.
The metric system provides standardized units for scientific measurements. For length, we use meters (m); for volume, liters (L); for mass, grams (g); and for temperature, either Celsius (°C) or kelvin (K). Time is measured in seconds (s) across both metric and SI systems.
Scientific notation allows us to express very large or small numbers efficiently. To convert a number to scientific notation, move the decimal point until you have a coefficient between 1 and 10, then note how many places you moved as the power of 10. Moving left gives a positive exponent (for large numbers), while moving right gives a negative exponent (for small numbers).
💡 Quick Tip: When converting between measurement systems, memorize key relationships like 1 inch = 2.54 cm and 1 kg = 2.20 lb. These conversions will appear repeatedly throughout chemistry and physics problems!

Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Metric prefixes help us express quantities that are much larger or smaller than the base unit. The prefixes range from femto (10⁻¹⁵) to peta (10¹⁵), with familiar ones including kilo (10³), milli (10⁻³), and micro (10⁻⁶). When you see 5.9 μL, it means 5.9 × 10⁻⁶ L.
Conversion factors are ratios that allow you to change from one unit to another while maintaining the same physical quantity. They're based on equalities—relationships that show two different ways of expressing the same amount. For example, since 1000 m = 1 km, we can write conversion factors as either or .
Real-world measurements often come with conversion factors built in. When a car travels at 65 km/hr, this tells you that 65 km equals 1 hour of travel time. Similarly, a 500 mg vitamin tablet means that 1 tablet contains 500 mg of the vitamin.
🔑 Remember: Always set up conversion factors so that your original units cancel out, leaving you with the desired units. This dimensional analysis approach helps prevent calculation errors!

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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Converting between units is a critical skill in chemistry. The process involves multiplying your initial measurement by the appropriate conversion factor, which is set up so that the original units cancel out. For example, to convert 5.0 hours to minutes, multiply by the factor to get 300 minutes.
Density is a fundamental property that relates the mass of a substance to its volume. It's calculated using the formula Density = mass/volume, typically measured in g/cm³ or g/mL for solids and liquids, and g/L for gases. This property is unique to each substance and helps identify unknown materials.
Density values provide useful equalities for calculations. For instance, knowing that lead has a density of 11.3 g/mL means that 11.3 g of lead equals 1 mL in volume. These relationships can be converted to fraction form and used as conversion factors in problem-solving.
🧪 Apply It: You can use density to find either mass or volume when the other is known. If you know a gold ring has a volume of 0.5 cm³ and gold's density is 19.3 g/cm³, you can calculate that the ring's mass is 9.65 g.

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Improve your grades
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Density calculations allow you to find the volume of a substance when you know its mass, or vice versa. The key is to treat density as a conversion factor between mass and volume. For example, if lead has a density of 11.3 g/mL, you can write this as the conversion factor 1 mL/11.3 g lead.
To solve a density problem, first identify what you know and what you need to find. Next, determine which conversion factors you'll need, including the density. Then set up your calculation so that the units cancel properly, leaving you with the unit you want in your answer.
In the example of finding the volume of a 23-gram sample of lead, you would multiply the mass (23 g) by the conversion factor to get approximately 2.0 mL. Notice how the grams cancel out, leaving you with the volume unit (mL) that you wanted.
📐 Pro Tip: When working with density problems, always check that your final answer makes physical sense. If you're calculating the volume of a heavy metal like lead, expect a small volume for a given mass because dense materials pack a lot of mass into a small space.
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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Guide on the Rules of Solubility
An essay about the vast applications of chemistry on different industries in the world.
Subatomic particles, notes on atoms, atomic number, mass number, neutrons, charge, electrons, protons, properties, loosing/gaining electrons and more
Understanding the dynamic nature of reversible reactions and the concept of chemical equilibrium, as well as calculating the equilibrium constant for reactions.
Explore the principles of dynamic equilibrium in closed systems, including Le Chatelier's Principle and factors affecting equilibrium position such as concentration, temperature, and pressure. This summary provides essential knowledge for Higher Chemistry students to understand how equilibrium can be manipulated to maximize product yield.
John Dalton's contributions to the model of the atom.
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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