What are the halogens?
The non-metal elements in Group 7 of the periodic table.
AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Higher · 5.1.2.6
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What are the halogens?
The non-metal elements in Group 7 of the periodic table.
How many electrons does a halogen atom have in its outer shell?
Seven.
Why do halogens have similar chemical reactions?
They have the same outer-shell structure: each atom needs to gain one electron for a full outer shell.
How are atoms arranged in elemental halogen molecules?
They form pairs of atoms (diatomic molecules).
How does the size of halogen molecules change down Group 7?
The molecules get larger.
How does the relative molecular mass of halogens change down Group 7?
It increases.
How do the melting and boiling points of halogens change down Group 7?
Both increase.
What type of compound forms when a halogen reacts with a metal?
An ionic halide salt, containing metal and halide ions.
How does a halogen atom form a halide ion in an ionic halide?
It gains one electron, forming an ion with a charge.
What type of compound usually forms when a halogen reacts with a non-metal, and how are its atoms bonded?
A covalent molecular compound; its atoms share electrons.