In this I/GCSE Chemistry blog post, we will be learning the features of group 1 in the periodic table, as well as the reactivity of these metals.
Group 1- Alkali Metals
Group 1 elements are all metals.
- They have a giant structure of positive ions surrounded by a sea of delocalised electrons.
- They all contain one electron in their outer shell.
- They form ionic compounds when they react with non-metals by losing an electron.
- They form cations with a 1+ charge.
All Group 1 metals react with water to produce metal hydroxides and hydrogen:
Metal + Water -----------> Metal Hydroxide + Hydrogen
Lithium: 2Li (s) + 2H O (l) -------> 2LiOH (aq) + H (g)
Sodium: 2Na (s) + 2H O (l) -------> 2NaOH (aq) + H (g)
Potassium: 2K (s) + 2H O (l) -------> 2KOH (aq) + H (g)
The metal hydroxides dissolve in the water and form strong alkaline solutions.
This property is the reason why the group 1 metals are often called the Alkali Metals.
The reactivity of the group 1 elements increases doen the group
- eg. caesium is more reactive than lithium.
The reactivity increases because it requires less energy to remove the outer electron dute to increased distance of the outer shell electron from the positive nucleus.
That is all for this post!
References:
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.toppr.com%2Fguides%2Fchemistry%2Fthe-s-block-elements%2Fgroup-1-elements-alkali-metals%2F&psig=AOvVaw3WgtdR6eJnx4VGrQShV-vB&ust=1628073577710000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCOiv4-7UlPICFQAAAAAdAAAAABAD