C4.1.2 - Group 7 : the halogens Flashcards
What are the names for the Group 7 elements?
The halogens
What are the properties of Group 7 elements?
They are brittle in solid state
They are poor conductors of electricity
They exist as diatomic molecules with weak intermolecular forces
They are coloured or form colour vapours in different states at room temperature
What is fluorine at room temperature?
A pale yellow gas
What is chlorine at room temperature?
A green gas
What is bromine at room temperature?
An orange-brown liquid that vaporises easily
What is iodine at room temperature?
A shiny grey-black crystalline solid that sublimed to form a purple vapour
What happens as you go down Group 7?
The density increases
The melting and boiling points increase
The reactivity decreases
Why are chlorine compounds added to swimming pool water?
To kill microorganisms
What happens if a halogen reacts with a metal?
It produces a salt
What happens to the reactivity of the halogens as you go down the group?
It decreases
What happens to halogens in reactions?
It gains an electron
Why is it easier for an atom to gain an outer electron, the more reactive it is?
The smaller the atom, the easier it is to grab an electron from another atom, making the atom more reactive. For example, chlorine is more reactive than iodine because its atoms gain an outer electron more easily than iodine atoms do as its atoms are smaller
