topic 6 groups in the periodic table Flashcards
what are group 1 metals known as
Alkali Metals
how many outer electrons do group 1 elements have
1 so they have similar chemical properties
what are the physical properties of group 1
low melting points and boiling points compared to other metals
very soft- they can be cut with a knife
what do alkali metals form
ionic compounds. they lose their single outer electron so easily that sharing it is out of the question, so they don’t form covalent bonds
do group 1 metals get more or less reactive as you go down
more reactive
why is the outer electron more easily lost
because its further from the nucleus (the atomic radius is larger) - so its less strongly attracted to the nucleus and less energy is needed to remove it
what happens when alkali metals are put in water and what is produced
they react vigorously, hydroxide and hydrogen gas
what is the equation for sodium and water
sodium + water -> sodium hydroxide + hydrogen
2Na+ 2H2 -> 2NaOH + H2
what happens to Lithium, sodium and potassium when put in water
-lithium will move around the surface, fizzing furiously
- sodium and potassium do the same, but they also melt in the heat of the reaction. Potassuim even gets hot enough to ignite the hydrogen gas being produced
what are group 7 elements known as
Halogens
how many electrons do halogens have in their outer shells
7
what happens as you go down group 7
the melting points and boiling points increase
what happens as you go down group 7
the melting points and boiling points increase
what are chlorine, bromine and iodine at room temperature
- Chlorine is a fairly reactive, poisonous, green gas
-Bromine is a poisonous, red-brown liquid which gives off an orange vapour at room temp
-Iodine is a dark grey crystalline solid which gives off a purple vapour when heated
how do you test for chlorine
hold a piece of damp blue litmus paper over it, chlorine will turn it white
