C2.19 Alkali Metals Flashcards
Describe the properties of an alkali metal
They are soft metals with low melting points
Describe the pattern in reactivity of the alkali metals lithium, sodium and potassium with water.
Lithium - floats on the surface and fizzy , gradually disappears
Sodium - reacts more vigorously than lithium and sodium also has a lower melting point. Reaction produces enough heat tho form a molten ball that whizzes around the surface of the water until reaction is complete. Sometimes hydrogen catches fire.
Potassium acts even more vigorously, hydrogen catches fire proucing a lilac flame.m
Why is caesium more reactive than lithium?
Because caesium has more electron shells in atoms than lithium , it is not held as strong as outer electron in a lithium atom. Ford between positive and negative charges is greatest when charges are close together.
Where are the alkali metals found?
In group 1
