The s-Block Elements – Notes

Alkali Metals: General Characteristics and Properties
The group1 metals are called the alkali metals. They are the most reactive metals.
They all have 1 valence electron and all form +1 cations.
The alkali metals are good conductors, and they have a shiny, silvery appearance.
In flame tests, lithium forms a candy-apple red colour, while sodium produces a yellow flame and potassium a lilac flame.
They react with hydrogen to form metal hydrides.
They react with halogens to form alkali metal halide salts, such as NaCl.
They react with oxygen – lithium forms oxides, sodium forms peroxides, and the other group 1 metals form superoxides.
Alkali metals react vigorously with water to produce hydroxide ions in solution, and hydrogen gas.

Alkali Metals: Anomalous Properties and Compounds
Lithium exhibits some anomalous behavior and it exhibits a “diagonal relationship” with magnesium.
Sodium carbonate, or washing soda, Na₂CO₃, can be formed by the four-step Solvay process.
Sodium Chloride, or table salt, NaCl, can be isolated from sea water.