Group 7 and 0- Halogens and Noble gases

Question 1

What are halogens also known as?

Answer 1

Group 7

Question 2

What elements are in group 7?

Answer 2

Fluorine, Chlorine, Bromine and Iodine ( there are two more but they are not too significant)

Question 3

What is fluorine?

Answer 3

A poisonous yellow gas, very reactive

Question 4

What is chlorine?

Answer 4

A less reactive, poisonous green gas.

Question 5

What is bromine?

Answer 5

A red/brown volatile liquid, poisonous.

Question 6

What is iodine?

Answer 6

A dark grey solid, that can form poisonous purple vapors, however it is also an antiseptic.

Question 7

What is a diatomic molecule?

Answer 7

Each molecule consists of two atoms. Halogens exists as diatomic molecules, meaning each element can exist as pairs of atoms, called diatomic molecules.They do this by sharing electrons and forming a covalent bond.

Question 8

What is a covalent bond?

Answer 8

When two atoms are joined, and so this allows each atom, to share an electron, giving each atom a full outer shell. We say that the atoms are joined by a “covalent bond”.

Question 9

Can halogens from covalent bonds with other non metals?

Answer 9

Yes.

Question 10

What compounds are formed if halogens form a covalent bond with other non metals?

Answer 10

e.g Hydrogen and fluorine would be Hydrogen fluoride.

Question 11

What are these compounds known as?

Answer 11

Simple molecular structures.

Question 12

What are the properties of group 7?

Answer 12

They can form covalent bonds with other non-metals, and their ions usually have a 1- charge (meaning they gain an electron).The further down the group you go, the melting and boiling points of the halogens increase, their reactivity decreasing.

Question 13

Describe the reactivity trend of the halogens.

Answer 13

For halogens, the melting and boiling points increase as you go down the group, the reactivity decreasing. The reactivity decreases because as you go down the group, the outermost shell gets further away from the positive nucleus, so the attractive force needed to pull in an extra electron from another atom gets weaker.If a halogen can’t attract and electron to complete its outer shell, then it is unable to react.

Question 14

What is a halide?

Answer 14

When a halogen gains an electron to form a 1- ion. e.g, a bromide ion.

Question 15

What are the halide halogens?

Answer 15

Change the end of the name to a DE, e.g fluorine becomes a fluoride, chlorine is then chloride.

Question 16

What is a displacement reaction?

Answer 16

A chemical reaction,when a more reactive metal displaces a less reactive metal .

Question 17

Can halogens displace one an another?

Answer 17

Yes. (E.g chlorine can displace bromine.) More reactive halogens can displace less reactive ones (e.g fluorine, chlorine and bromine can displace iodine as it is the least reactive.)

Question 18

What are group 0 elements also known as?

Answer 18

Noble gases.

Question 19

What are the properties of noble gases?

Answer 19

They exist as colorless gasses, they are inert, and unreactive. They exist as single atoms due to this, and the cannot be set on fire.

Question 20

Why are noble gases inert?

Answer 20

They have full outer shells, which means they don’t react with anything.

Question 21

Does the boiling point for noble gases increase or decrease as you go down the group?

Answer 21

Increase.

Question 22

What colour are halide salts of halogens?

Answer 22

Colorless

Question 23

What color is bromine water?

Answer 23

Orange

Question 24

What color is chlorine water?

Answer 24

Colorless

Question 25

What color is iodine water?

Answer 25

Brown

Question 26

How do we determine the reactivity of a halogen?

Answer 26

By mixing halide salt and halogen waters and seeing if a reaction occurs.

Question 27

What color do you get if yo mix potassium chloride and bromine water?

Answer 27

No reaction

Question 28

Potassium chloride and iodine water.

Answer 28

No reaction

Question 29

Potassium chloride and chlorine water?

Answer 29

No reaction

Question 30

Potassium bromide and chlorine water?

Answer 30

Orange solution, bromide is displaced.

Question 31

Potassium bromide and bromine water ?

Potassium bromide and iodine water?

Answer 31

No reaction for both as iodine is not as reactive as bromine and so can’t displace it.

Question 32

Potsssium iodide and chlorine water

Answer 32

Brown solution, iodine is displaced

Question 33

Potassium iodide and bromine water?

Answer 33

Brown solution and iodine is displaced because it is least reactive.

Question 34

Potassium iodide and iodine water

Answer 34

No reaction as you can’t displace iodine with iodine.

Question 35

Explain how displacement reactions can be used not show the relative reactivity of chlorine, bromine and iodine.

Answer 35

1.explain what a displacement reaction is.
2. Choose suitable reactants to show off the reactivity if bromine and chlorine.
3.describe the changes you would observe (e.g before it was a pale yellow and after it is…..)
4.Write a balanced symbol equation for your reaction.
5.repeat with bromine and iodine and chlorine and iodine.