Additional Science Chemistry- Group 1 and 7 elements

Group 1 and group 7 elements

Group 1 elements

Group 1 elements are known as alkaline metals.

Properties:

• Dull coloured metals.
• Soft so you can cut them with a knife.
• Stored in oil otherwise they would react with the air.
• Good conductor of heat and electricity.
• Shiny when cut but tarnish rapidly.

Reactions:

Violent reaction with water. Hydrogen gas is produced.
Test for Hydrogen gas: put a lighted splint in tube- gives off a squeaky pop.
Metal hydroxide solutions which are alkaline are formed in the reaction. Hence they are known as alkaline metals.
Lithium, Sodium and Potassium are less dense than water so they float during reactions. Rubidium and Caesium sink.

Equation for the reaction:

2Li + 2H2O ---> 2LiOH + H2

Similarities:

1.  React in the same way because they have 1 electron in their last shell. The electron can be lost easily leaving a positive ion. Ions have a noble gas structure.
2.  Form ionic compounds with similar formulae.
3.  Burn to form oxides with formula X2O (X= metal.)
4.  React with chloride to form metal chloride with formula XCl.

Differences:

1.  Their properties become more reactive as you go down the group. They…