Sc17a - Alkali Metals Flashcards
What are properties of alkali metals ?
-Low M.P
-Soft and easy to cut
-reactive with metals so must be stored in oil.
How does lithium react with water
Lithium + water -)> bubbles fiercely on the surface.
How does sodium react with water
Sodium + water -> melts into a ball and fizzes about the surface.
How does potassium react with water.
Potassium + water -> bursts into lilac flames and flies about the surface
(Seneca) what happens when an alkali metal reacts with water ?
Enough energy is released to melt the metal and the metal floats on the surface of the water.
What happens when a halogen reacts with a metal ?
When a metal atom transfers its outer electron to a non-metal atom (like a group 7 atom), salts are formed.
The result is a compound where all the ions have a full outer shell.
Reactivity of halogens down the group.
As you go down the group, the halogens become less reactive. This is because:The atoms gain more electron shells.The outer electron shell is further from the nucleus.The attraction between the nucleus and the electron (to be gained from another element) decreases.
What type of ion do halogens form ?
Halogens form negative ions