group 7 Flashcards
(15 cards)
What group do halogens belong to on the periodic table?
Group 7.
Are halogens metals or non-metals?
Halogens are non-metals.
What type of molecules do halogens form?
Halogens form diatomic molecules (e.g. Cl₂, Br₂).
What happens to the reactivity of halogens as you go down Group 7?
Reactivity decreases as you go down the group.
What happens to melting and boiling points as you go down Group 7?
Melting and boiling points increase.
What happens to the relative atomic mass of halogens as you go down the group?
It increases.
What is the trend in colour and state of halogens as you go down the group?
They become darker in colour and change from gases to liquids to solids.
What colour is chlorine gas?
Pale green gas.
What colour is bromine at room temperature?
Red-brown liquid with orange vapour.
What colour is iodine at room temperature?
Dark grey solid with purple vapour when heated.
What kind of bond do halogens form with metals?
Ionic bonds, forming halide ions (e.g. Cl⁻, Br⁻, I⁻).
What happens when a halogen gains one electron?
It forms a halide ion with a -1 charge.
What is a displacement reaction in Group 7?
A more reactive halogen displaces a less reactive halogen from an aqueous solution of its salt.
Give an example of a displacement reaction involving chlorine and potassium bromide.
Cl₂ + 2KBr → 2KCl + Br₂
Why does reactivity decrease down Group 7?
The outer shell is further from the nucleus, so it’s harder to gain an electron due to weaker attraction.
