Group 1, 7, and 0 elements: Properties and reactions
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Mina
25/08/2025
Chemistry
C4 chem revision notes
274
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25 Aug 2025
•
GCSE Chem Revision: Group 1, 7, 0 Reactivity, C4, Transition Metals & Gas Tests
Mina
@mvna_aaaa
Transition Metals and Their Properties
Transition metals are a group of elements with unique properties that set them apart from other metals. They are located in the d-block of the periodic table and play crucial roles in various chemical and industrial processes.
Key properties of transition metals:
- Higher melting points compared to other metals
- Higher densities than most other elements
- Ability to form ions with multiple charges (e.g., Iron(II) and Iron(III))
- Formation of colored compounds
- Catalytic properties useful in various chemical reactions
Highlight: The ability of transition metals to form colored compounds is due to their partially filled d-orbitals, which allow for electronic transitions that absorb specific wavelengths of light.
Example: Copper(II) compounds often appear blue, while Iron(III) compounds tend to have a reddish-brown color.
Tests for Gases
Identifying gases is an essential skill in chemistry. Here are some common tests for important gases:
-
Carbon Dioxide (CO₂):
- Turns limewater milky or cloudy
-
Chlorine (Cl₂):
- Bleaches blue litmus paper
-
Oxygen (O₂):
- Relights a glowing splint
-
Hydrogen (H₂):
- Burns with a "squeaky pop" sound
Vocabulary: Limewater - A solution of calcium hydroxide used to test for the presence of carbon dioxide.
Tests for Aqueous Cations
Identifying cations (positively charged ions) in aqueous solutions is often done by adding sodium hydroxide (NaOH) and observing the resulting precipitate. Here are some common reactions:
- Copper(II): Forms a blue precipitate
- Iron(II): Forms a green precipitate
- Iron(III): Forms an orange/brown precipitate
- Zinc: Forms a white precipitate that redissolves in excess NaOH
- Aluminium: Forms a white precipitate
- Magnesium: Forms a white precipitate
Definition: A cation is a positively charged ion formed when an atom loses one or more electrons.
Tests for Halides
To test for halide ions (Cl⁻, Br⁻, I⁻), add dilute nitric acid followed by silver nitrate. The resulting precipitates indicate the presence of specific halides:
- Chloride: White precipitate
- Bromide: Cream precipitate
- Iodide: Yellow precipitate
Example: In a solution containing chloride ions, adding silver nitrate will produce a white precipitate of silver chloride (AgCl).
Tests for Anions
-
Carbonates (CO₃²⁻):
- React with dilute acids to produce carbon dioxide
- CO₂ turns limewater milky, forming a white calcium carbonate precipitate
-
Sulfates (SO₄²⁻):
- Form a white precipitate when barium chloride is added
Vocabulary: Anion - A negatively charged ion formed when an atom gains one or more electrons.
Flame Tests
Flame tests are used to identify certain metal ions based on the characteristic color they produce when heated in a flame:
- Lithium: Red
- Sodium: Yellow
- Potassium: Lilac
- Copper: Green
- Calcium: Orange/red
Highlight: Flame tests are a quick and simple way to identify the presence of certain metal ions in a sample, particularly useful for Group 1 elements like sodium and potassium.
Group 1 Alkali Metals
Group 1 elements, also known as alkali metals, become more reactive as you move down the group. These elements have a single electron in their outer shell, making them highly reactive.
Key reactions of Group 1 metals:
- Form oxides when reacting with oxygen
- Produce white precipitates when reacting with chlorine
- React with water to create alkaline solutions and hydrogen gas
Vocabulary: Precipitate - A solid that forms and separates from a solution during a chemical reaction.
Highlight: The reactivity of Group 1 elements increases as you move down the periodic table, making elements like rubidium and cesium extremely reactive.
Group 7 Halogens
Halogens are non-metallic elements in Group 7 that are known for their toxicity and reactivity. They have seven electrons in their outer shell and form diatomic molecules (F₂, Cl₂, Br₂, I₂).
Key properties of halogens:
- React with metals to form ionic compounds
- Decrease in reactivity as you move down the group
- Form negative ions in reactions
Example: Chlorine (Cl₂) is more reactive than bromine (Br₂), which is more reactive than iodine (I₂).
Group 0 Noble Gases
Noble gases, found in Group 0, are characterized by their extremely low reactivity due to their full outer electron shells. This stable electron configuration makes them inert under most conditions.
Properties of noble gases:
- Unreactive due to full outer electron shells
- Boiling point increases as you move down the group
Definition: Noble gases are a group of chemical elements with full outer electron shells, making them extremely stable and unreactive under normal conditions.
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Thomas R
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Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
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This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
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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
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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
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
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 apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
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
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
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
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
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 apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
GCSE Chem Revision: Group 1, 7, 0 Reactivity, C4, Transition Metals & Gas Tests
Mina
@mvna_aaaa
Group 1, 7, and 0 elements: Properties and reactions
This chemistry revision guide covers the key properties and reactions of Group 1 (alkali metals), Group 7 (halogens), and Group 0 (noble gases) elements, as well as transition metals and gas... Show more
Transition Metals and Their Properties
Transition metals are a group of elements with unique properties that set them apart from other metals. They are located in the d-block of the periodic table and play crucial roles in various chemical and industrial processes.
Key properties of transition metals:
- Higher melting points compared to other metals
- Higher densities than most other elements
- Ability to form ions with multiple charges (e.g., Iron(II) and Iron(III))
- Formation of colored compounds
- Catalytic properties useful in various chemical reactions
Highlight: The ability of transition metals to form colored compounds is due to their partially filled d-orbitals, which allow for electronic transitions that absorb specific wavelengths of light.
Example: Copper(II) compounds often appear blue, while Iron(III) compounds tend to have a reddish-brown color.
Tests for Gases
Identifying gases is an essential skill in chemistry. Here are some common tests for important gases:
-
Carbon Dioxide (CO₂):
- Turns limewater milky or cloudy
-
Chlorine (Cl₂):
- Bleaches blue litmus paper
-
Oxygen (O₂):
- Relights a glowing splint
-
Hydrogen (H₂):
- Burns with a "squeaky pop" sound
Vocabulary: Limewater - A solution of calcium hydroxide used to test for the presence of carbon dioxide.
Tests for Aqueous Cations
Identifying cations (positively charged ions) in aqueous solutions is often done by adding sodium hydroxide (NaOH) and observing the resulting precipitate. Here are some common reactions:
- Copper(II): Forms a blue precipitate
- Iron(II): Forms a green precipitate
- Iron(III): Forms an orange/brown precipitate
- Zinc: Forms a white precipitate that redissolves in excess NaOH
- Aluminium: Forms a white precipitate
- Magnesium: Forms a white precipitate
Definition: A cation is a positively charged ion formed when an atom loses one or more electrons.
Tests for Halides
To test for halide ions (Cl⁻, Br⁻, I⁻), add dilute nitric acid followed by silver nitrate. The resulting precipitates indicate the presence of specific halides:
- Chloride: White precipitate
- Bromide: Cream precipitate
- Iodide: Yellow precipitate
Example: In a solution containing chloride ions, adding silver nitrate will produce a white precipitate of silver chloride (AgCl).
Tests for Anions
-
Carbonates (CO₃²⁻):
- React with dilute acids to produce carbon dioxide
- CO₂ turns limewater milky, forming a white calcium carbonate precipitate
-
Sulfates (SO₄²⁻):
- Form a white precipitate when barium chloride is added
Vocabulary: Anion - A negatively charged ion formed when an atom gains one or more electrons.
Flame Tests
Flame tests are used to identify certain metal ions based on the characteristic color they produce when heated in a flame:
- Lithium: Red
- Sodium: Yellow
- Potassium: Lilac
- Copper: Green
- Calcium: Orange/red
Highlight: Flame tests are a quick and simple way to identify the presence of certain metal ions in a sample, particularly useful for Group 1 elements like sodium and potassium.
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Group 1 Alkali Metals
Group 1 elements, also known as alkali metals, become more reactive as you move down the group. These elements have a single electron in their outer shell, making them highly reactive.
Key reactions of Group 1 metals:
- Form oxides when reacting with oxygen
- Produce white precipitates when reacting with chlorine
- React with water to create alkaline solutions and hydrogen gas
Vocabulary: Precipitate - A solid that forms and separates from a solution during a chemical reaction.
Highlight: The reactivity of Group 1 elements increases as you move down the periodic table, making elements like rubidium and cesium extremely reactive.
Group 7 Halogens
Halogens are non-metallic elements in Group 7 that are known for their toxicity and reactivity. They have seven electrons in their outer shell and form diatomic molecules (F₂, Cl₂, Br₂, I₂).
Key properties of halogens:
- React with metals to form ionic compounds
- Decrease in reactivity as you move down the group
- Form negative ions in reactions
Example: Chlorine (Cl₂) is more reactive than bromine (Br₂), which is more reactive than iodine (I₂).
Group 0 Noble Gases
Noble gases, found in Group 0, are characterized by their extremely low reactivity due to their full outer electron shells. This stable electron configuration makes them inert under most conditions.
Properties of noble gases:
- Unreactive due to full outer electron shells
- Boiling point increases as you move down the group
Definition: Noble gases are a group of chemical elements with full outer electron shells, making them extremely stable and unreactive under normal conditions.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
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
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
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
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
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 apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
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
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
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
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
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 apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user