GROUP 7 - HALOGENS Flashcards
What type are Group 7?
Non-metals
What are Group 7 also known as ?
Halogens
Why is this group important?
They form many compounds using covalent bonding and ionic bonding
How many electrons do these elements have in their outer shell?
7
How many electrons do they need to become a full outer shell?
1
What is fluorine used to make?
Toothpaste
Antiseptics
creams
Used to make hydrogen fluoride to make non stick pots and pans
Use of chlorine?
Kills germs in water
Antiseptics
TCP
Used to make PVC plastic
Double glazed windows
Bleach
How do halogens form ionic compounds?
By gaining an electron from the metal atom.
How do halogens form covalent compounds?
By sharing the outer electrons.
Use of Bromine?
Antiseptics
Film photography
To distinguish a saturated and non saturated compound.
Uses of Iodine?
Iodine is used as a test for starch
Iodine is a red/brown liquid and turns blue-black if starch is present
To make hormone thyroxide(controls metabolism)
Antiseptic
What are the trends as you go down the groups in the periodic table?
1) Atom size increases
2) They get darker in colour
3) Change of state
Fluorine and Chlorine=Gases
Bromine=Liquid
Iodine and Astatine= Solids
4)Melting and boiling points increase
-Stronger intermolecular forces between molecules(hence the change of state)
5) Reactivity decreases
How do Group 7 elements form covalent compounds?
When they react with other non metal elements.
What happens when a halogen reacts with a metal?
It gains one electron and becomes a negative ion.
When halogens form negative ions what does the name end with. Can you give an example.
“ide”
Fluoride
Chloride
Iodide
Bromide
