The Alkali Metals THE PERIODIC TABLE Flashcards
What group are the alkali metals?
Group 1.
What are the properties of alkali metals?
They are very reactive.
Their reactivity increases as you go down the group.
They have very low densities-they can float on water.
Very soft.
To begin with they have shiny, silvery surfaces. This goes dull when cut as it reacts with oxygen.
Why are they reactive?
They only have to lose one electron to receive a stable electronic structure.
What do they react with?
Non-metals.
What is the pattern with their boiling and melting points?
The boiling and melting points get lower as you go down the group.
What happens to lithium, sodium or potassium when it reacts with water?
Floats, moves around and fizzes. The fizzing happens because the metals reacts with the water to form hydrogen gas.
Potassium reacts very vigorously, causing it to ignite. The flame is lilac because of the potassium ions formed in the reaction.
A metal hydroxide is produced.
What what happens when alkali metals react with non-metals such as chlorine?
React vigorously. They produce metal chlorides which are white solids. The metal chloride dissolved in the water to form colourless solutions.
