Group 7

Front 1

What are the group 7 elements?

Back 1

They are known as halogens and they include fluorine, chlorine, bromine, iodine and astatine

Hint 1

Names and general name

Front 2

Physical properties

Back 2

Have low melting and boiling points. They are less reactive down a group. They exist as diatomic molecules. The boiling points increase generally down a groups and the physical state goes from gas to liquid to solid down the group.

Hint 2

M+B points, reactivity, boiling point, physical state.

Front 3

Electronic configuration

Back 3

They have seven electrons on the outer shell. Their highest energy level is in the p sub shell and the elements are in the p block of the periodic table.

Hint 3

Outer electrons and sub shell

Front 4

Group seven electrons

Back 4

They have one electron fewer than the electronic configuration of a noble gas. And in their p sub shell they contain five electrons.

Hint 4

Noble gas and p sub shell

Front 5

Halogens oxidation states.

Back 5

Most reactive non metals and are strong oxidising agents. This means they gain electrons from other elements to make the other elements oxidised. The level of oxidising reduces down the group.

Hint 5

Non metals. Oxidising agents.

Front 6

Oxidising power?

Back 6

This is the measure of the strength of a halogen with which it is able to attract and capture and electron to form a halide ion.

Hint 6

Measure, capture, ion.

Front 7

Redox reaction of halogen.

Back 7

In w redox reaction a halogen will gain an electron to form a halide ion with the charge of 1- the electron gained is added to the p sub shell.

Hint 7

Halide of charge

Front 8

Reactivity decreases down a group because?

Back 8

The atomic radius increases and the electronic shielding increases and the oxidising power decreases.

Hint 8

Radius, shielding, power.

Front 9

Displacement reaction

Back 9

A halogen will be mixed with a solution of a different halide ion and the more reactive halogen will oxidise and displace a halide of the less reactive halogen.

Hint 9

Reactivity

Front 10

Reactivity in a reaction.

Back 10

As the reactivity down group seven decreases the higher the halogen in the group the most likely it is to displace the other halogen which will be lower than it. For example chlorine will displace iodine and bromine.

Hint 10

Displacement

Front 11

Disproportionation

Back 11

Is a reaction where an element is both reduced and oxidised. Chlorine reacting with water to form hydrochloric acid and chloric (1) acid.

Hint 11

Redox
Chlorine

Front 12

Bleach

Back 12

Chlorine makes bleach which is why it can be toxic but we have to control the amount used in water in order to prevent damage and intoxication.

Hint 12

NaClO

Front 13

Properties of compounds and elements?

Back 13

Less reactive down the group
Elements react with metals to form ionic halide with a 1- charge.

Hint 13

Reactivity and metals reaction

Front 14

Bonding, structure, redox character and reactivity.

Back 14

They are bonded by covalent bonds between diatomic molecules. They have a simple molecular structure with weak van Der waals forces between diatomic molecules. They are oxidising agents and react by gaining electrons to form halide ions of -1. The reactivity decreases down the group.

Hint 14

Diatomic
Van Der waals

Front 15

Flourine

Back 15

Most reactive element known
Can be explosive in a reaction.
Pale green coloured gas.
It reacts with a lot of substances so it is hard to store (glass and steel and noble gas).

Hint 15

Reactivity, colour and state, disadvantage

Front 16

Halides examples

Back 16

Sodium chloride is a common salt.
Sodium fluoride are found in toothpaste.
Crystals of calcium fluoride are used to make infrared light focused on lenses.

Hint 16

NaCl
NaF
CaF2

Front 17

Chlorine

Back 17

Is a toxic gas and is added in small amounts to water to remove bacteria. It has prevented cholera outbreaks but can be the cause of cancer. It's reaction with organic substances forms hydrocarbons that are toxic.

Hint 17

It's disadvantage
It's use.

Front 18

Test for halides.

Back 18

Halide ions can be detected by a test tube test.
Put an unknown halide substance in water to dissolve. Then add silver nitrate (AgNO3) in an aqueous solution. The silver ions will react with the halide ions to form a silver halide precipitate. You can recognise the ion from its colour. If not then add ammonia to show different solubilities.

Hint 18

Dissolve
Silver nitrate
Precipitate
Ammonia.

Front 19

Colours of halide test for Br Cl and I

Back 19

Br ➡️ cream precipitate ➡️ soluble
Cl ➡️ White precipitate ➡️ soluble in dilute
I. ➡️ yellow precipitate ➡️ insoluble

Hint 19

White
Cream
Yellow
And solubility.

Front 20

Precipitation reaction:

Back 20

A reaction that takes place in aqueous solution when aqueous ions react to form a solid precipitate.

Hint 20

Aqueous