group 1 and 2 elements

What does the reactivity of metals depend on?

Reactivity of metals depends on their tendency to lose electrons.

When are metals more reactive?

Metals are more reactive when they have a higher tendency to lose electrons.

How does the reactivity of Group 1 and 2 elements change down the group?

The reactivity of both groups 1 and 2 increases as you go down these groups.

What explains this trend in reactivity?

It is explained by the decrease in ionisation energy (IE).

Why does ionisation energy decrease down the group?

IE decreases due to an increase in electron shielding and a decrease in effective nuclear charge.

Which elements are the least reactive in Groups 1 and 2 based on ionisation energy trends?

Lithium and beryllium are the least reactive metals in Groups 1 and 2, respectively.

Why are Group 2 metals less reactive than Group 1 metals?

Group 2 metals have more ionisation energy and a more effective nuclear charge.

What does this imply about the tendency of Group 2 metals to lose electrons?

Group 2 metals have a lower tendency to lose electrons compared to Group 1 metals.

Where are the most reactive metals found in Groups 1 and 2?

At the bottom of both groups-caesium and barium.

What ions do Group 1 metals form when they react?

They form M+ ions because they have only one valence electron.

What ions do Group 2 metals form?

They lose both valence electrons to form M2+ ions.

How do Group 1 and 2 metals react with common reagents?

They react similarly with oxygen, chlorine, and water.

How does reactivity change within each group?

Metals at the bottom of the group react more vigorously than those at the top.

How do Group 1 elements react with oxygen?

React violently when heated to produce metal oxides (M2O).

How do Group 2 elements react with oxygen?

React when heated to produce metal oxides (MO).

How do Group 1 elements react with chlorine?

React violently when heated to produce metal chlorides (MCl).

How do Group 2 elements react with chlorine?

React when heated to produce metal chlorides (MCl2).

How do Group 1 elements react with water?

React violently with cold water to produce metal hydroxide (MOH) and hydrogen gas (H2).

How does beryllium behave with water?

Beryllium does not react with water.

How do other Group 2 metals behave with water?

They react with cold water to produce metal hydroxide M(OH)2 and hydrogen gas.

How does magnesium react with water?

Slowly with cold water to form Mg(OH)2 and H2; with steam, it forms MgO and H2.

What is a notable physical property of Group 1 and 2 compounds?

All Group 1 and 2 compounds have a white colour.

What is the nature of Group 1 and 2 oxides?

They are basic and react well with both water and acids.

What happens when Group 1 or 2 oxides react with water?

They form metal hydroxides.

How does magnesium oxide react with water?

Very slowly.

Is there any exception among Group 2 oxides?

Yes, beryllium oxide is an exception-it does not react with water.

How do oxides of either group react with dilute acids?

They undergo neutralisation reactions to produce salt and water.

How does the solubility of Group 2 hydroxides change down the group?

Solubility increases as you go down the group.

Which Group 2 hydroxide is most soluble?

Barium hydroxide.

How does the solubility of Group 2 sulfates or carbonates change down the group?

It follows the opposite trend of hydroxides; solubility decreases down the group.

Which Group 2 sulfate is least soluble?

Barium sulfate.

What is the reaction of barium with sulfate used for?

Barium forms a white precipitate with sulfate, which is used to test for the presence of the sulfate ion.

What is the chemical equation for this test?

Ba²⁺(aq) + SO₄²⁻(aq) → BaSO₄(s)