Group 1 Elements

Question 1

What are the properties of a group 1 element?

Answer 1

• They are alkali metals
• They all have 1 electron in their outer shell which makes them very reactive and gives them similar properties
• The alkali metals are all soft and have low density
• Trends for the alkali metals going down group 1 are:
• increasing radioactivity - the outer electron is more easily lost as the attraction between the nucleus and electron decreases as the electron is further away from the nucleus the down the group you go
• lower melting and boiling points
• higher relative atomic mass

Question 2

Do Group 1 elements require a large amount of energy to form an ionic compound?

Answer 2

The group 1 elements don’t need much energy to lose their one outer electron to form a full outer shell, so they readily form 1+ ions. This makes it easy for them to form an ionic compounds, these compounds are generally white solids that dissolve in water to form colourless solutions.

Question 3

What does a reaction with water produce?

Answer 3

Eg
2Na(s) + 2H2O(l) -> 2NaOH(aq) + H2(g)
sodium + water -> sodium hydroxide + hydrogen

Question 4

What does a reaction with chlorine produce?

Answer 4

2Na(s) + Cl2(g) -> 2NaCl(s)
sodium + chlorine -> sodium chloride
Group 1 metals react vigorously when heated in chlorine gas to form white salts called metal chlorides. As you go down the group, reactivity increases so the reaction with chlorine gets more vigorous.

Question 5

How do the group 1 metals react with oxygen?

Answer 5

Group 1 metals can react with oxygen to form a metal oxide, different types of oxide will form depending on the group 1 metal
E.g
Lithium reacts to form lithium oxide (Li2O)
Sodium reacts to form a mixture of sodium oxide (Na2O) and sodium peroxide (Na2O2)
Potassium reacts to form a mixture of potassium peroxide (K2O2) and potassium (KO2)