C9 - Periodic table

Question 1

Group I metals

Answer 1

The Group I metals are also called the alkali metals as they form alkaline solutions with high pH values when reacted with water
* lithium, sodium, potassium, rubidium, caesium and francium
* all have one electron on outer shell

Question 2

Physical properties of Group 1 metals (4)

Answer 2

• Are soft and easy to cut, getting even softer and denser as you move down the Group (sodium and potassium do not follow the trend in density)
• Have shiny silvery surfaces when freshly cut
• Conduct heat and electricity
• They all have low melting points and low densities compared to other metals, and the melting point decreases as you move down the Group

Question 3

Chemical properties of Group 1 metals (3)

Answer 3

• They react readily with oxygen and water vapour in air so they are stored under oil to stop them from reacting
• Group I metals will react similarly with water, reacting vigorously to produce an alkaline metal hydroxide solution and hydrogen gas
• The Group I metals get more reactive as you look down the group, so only the first three metals are allowed in schools for demonstrations

Question 4

Predicting rubidium reaction with water

Answer 4

• Explodes with sparks
• Rubidium hydroxide is produced

Question 5

Predicting caesium reaction with water

Answer 5

• Violent explosion due to rapid production of heat and hydrogen
• Caesium hydroxide is produced

Question 6

Predicting francium reaction with water

Answer 6

• Too reactive to predict

Question 7

Halogens

Answer 7

These are the Group VII non-metals that are poisonous and include fluorine, chlorine, bromine, iodine and astatine
* are diatomic
* have seven electrons in their outer shell

Question 8

Halide ions

Answer 8

When halogens create bonds with another atom to form a negatively charged ion

Question 9

Properties of halogens

Answer 9

• At room temperature (20 °C), the physical state of the halogens changes as you go down the group
• Chlorine is a pale yellow-green gas, bromine is a red-brown liquid and iodine is a grey-black solid
• Reactivity increases as you go up the group

Question 10

Predicting melting and boiling points of halogens

Answer 10

The melting and boiling point of the halogens increases as you go down the group

Question 11

Predicting physical states of halogens

Answer 11

The halogens become denser as you go down the group
* bottom is a solid

Question 12

Predicting the colour of halogens

Answer 12

The colour of the halogens becomes darker as you go down the group
* Fluorine is yellow
* Astatine is black

Question 13

Transition elements

Answer 13

A collection of metals having high densities, high melting points and forming coloured compounds, and which, as elements and compounds, often act as catalysts

Question 14

Noble gases

Answer 14

The noble gases are in Group VIII (or Group 0); they are non-metals and have very low melting and boiling points
* all monoatomic, colourless gases

Question 15

Noble gas reaction

Answer 15

They have full outer shells
* are extremely stable so these elements are unreactive or inert