Group 7 (periodic table)

Question 1

Name Group 7 of the Periodic Table.

Answer 1

Group 7 of the Periodic Table is the called the halogens.

Question 2

Explain why fluorine is in Group 7 of the Periodic Table.

Answer 2

Fluorine is in Group 7 of the Periodic Table because it has 7 electrons in its outer shell.

Question 3

Give the colour and state of chlorine at room temperature.

Answer 3

The colour and state of chlorine at room temperature is a green gas.

Question 4

Describe what happens to the melting points of the halogens going down the group.

Answer 4

Going down the group, melting points of the halogens decreases.

Question 5

Write the word equation for the displacement reaction between potassium bromide and chorine.

Answer 5

The word equation for the displacement reaction between potassium bromide and chlorine is:

potassium bromide + chlorine → potassium chloride + bromine

Question 5

What is meant by a halogen displacement reaction?

Answer 5

A halogen displacement reaction is one where a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide.

Question 6

Write the balanced symbol equation for the reaction between potassium iodide and bromine.

Answer 6

The balanced symbol equation for the reaction between potassium iodide and bromine is:

Br2 + 2KI → 2KBr + I2

Question 7

Explain why iodine cannot displace chlorine from potassium chloride.

Answer 7

Iodine cannot displace chlorine from potassium chloride because iodine is less reactive than chlorine.

Question 8

Give the charge of the ions formed when halogens react with Group 1 metals.

Answer 8

The charge of the ions formed when halogens react with Group 1 metals is 1-.

Question 8

Explain why chlorine has a higher melting point than fluorine.

Answer 8

Chlorine has a higher melting point than fluorine because there are stronger intermolecular forces which need more energy to overcome.

Question 9

Define the term reactivity.

Answer 9

Reactivity is the tendency of a substance to undergo a chemical reaction by losing or gaining electrons.

Question 9

Describe the trend in reactivity of the halogens going down the group.

Answer 9

The trend in reactivity of the halogens is, going down the halogen, reactivity decreases.

Question 10

What are halide ions?

Answer 10

Halide ions are ions formed when halogen atoms gain an electron, carrying a 1- charge

Question 11

Give the electronic configuration of a a chlorine atom.

Answer 11

The electronic configuration of a chlorine atom is 2.8.7.

Question 12

Why is fluorine the most reactive halogen?

Answer 12

Fluorine is the most reactive halogen because it has the fewest shells so it is easier for the nucleus to attract an electron.

Question 13

True or False?

It becomes easier for halogen atoms to gain electrons as you go down the group.

Answer 13

False.

It becomes harder for halogen atoms to gain electrons as you go down the group making them less reactive.

Question 14

Explain why reactivity decreases going down Group 7.

Answer 14

Reactivity decreases going down Group 7 because the atoms have more shells, meaning there is a less attraction between an incoming electron and the positive nucleus making it harder to gain an electron.