GCSE Chemistry Revision "Group 7 Part 2 Compounds of the Halogens"

Summary

In this video, we explore how Group 7 elements, also known as the halogens, form covalent and ionic compounds. The halogens, such as fluorine and chlorine, have seven electrons in their outer energy levels and form covalent bonds when reacting with non-metals, as seen in compounds like hydrogen chloride and carbon bromide. However, when halogens react with metals, they form ionic compounds by gaining one electron from the metal, resulting in ions with a negative charge, like chloride ions. This concept is demonstrated through reactions involving lithium and chlorine, among others.

Takeaways

• 😀 Group 7 elements are also called halogens and are located on the right of the periodic table. They are non-metals.
• 😀 Halogens have seven electrons in their outer energy level, which is crucial for their reactivity.
• 😀 When group 7 elements react with non-metals, they form covalent compounds by sharing electrons.
• 😀 For example, fluorine (F) and chlorine (Cl) form molecules like F2 and Cl2, with two atoms joined by a covalent bond.
• 😀 The covalent bond between atoms involves the sharing of electron pairs to achieve full outer energy levels.
• 😀 Halogens form covalent compounds with other non-metals, such as hydrogen chloride (HCl) formed by hydrogen and chlorine.
• 😀 The bond in hydrogen chloride can be represented by a stick showing the shared covalent bond.
• 😀 Halogens also form covalent compounds with elements like carbon (C) and phosphorus (P), as seen in bromine-carbon and iodine-phosphorus examples.
• 😀 When halogens react with metals, they form ionic compounds instead of covalent ones.
• 😀 In ionic compounds, halogens like chlorine gain an electron from the metal atom, turning them into negatively charged ions (e.g., chloride ion).
• 😀 All halogen ions have a negative charge of -1, and their names end with 'ide' (e.g., fluoride for fluorine, chloride for chlorine).

Q & A

What are group seven elements also known as?

Group seven elements are also known as the halogens.

Where are halogens located on the periodic table?

Halogens are located on the right side of the periodic table.

What is the key characteristic of halogens in terms of their electron configuration?

Halogens have seven electrons in their outer energy level.

How do group seven elements form covalent compounds?

Group seven elements form covalent compounds by sharing electrons with other non-metal elements to achieve a full outer energy level.

Can you provide an example of a covalent compound formed by a halogen and a non-metal?

An example is hydrogen chloride (HCl), where chlorine (a halogen) and hydrogen (a non-metal) share an electron to form a covalent bond.

What is the bond type formed between halogens and non-metals?

The bond type formed between halogens and non-metals is a covalent bond, where electrons are shared between atoms.

What happens when halogens react with metals?

When halogens react with metals, they gain an electron from the metal, forming negatively charged ions and resulting in ionic compounds.

How does chlorine react with lithium to form an ionic compound?

When chlorine reacts with lithium, lithium gives one electron to chlorine, making chlorine a negatively charged chloride ion (Cl⁻) and lithium a positively charged ion (Li⁺).

What happens to the charge of a halogen atom when it gains an electron?

When a halogen atom gains an electron, it becomes negatively charged, forming an ion with a charge of -1.

What is the name change when halogens form ions?

When halogens form ions, their names change by adding 'ide' to the end. For example, fluorine becomes fluoride (F⁻), and chlorine becomes chloride (Cl⁻).