Group 1 - Alkali metals

Group 1 - Alkali metals

(Group = vertical column)

ALL group 1 metals have 1 atom on the most outer

Alkali metals have these trends as you go DOWN the group.

• Atoms grow LARGER
• MORE reactive
• HIGHER density
• SOFTER to cut
• LOWER melting and boiling points

BIGGER ATOMS-

As you go down the group, each atom has an extra energy shell. Making the atom itself larger

MORE REACTIVE-

Since the nucleus has the force to hold the electrons, the easier it is to lose an electron (since, the force on the electron isn't as strong)

SO. since group 1 metals want to LOSE their electrons, they get more reactive as you go down the group (as the atoms grow bigger)

HIGHER DENSITY-

Alkali metals have low densities - they float. (atoms grow larger, higher densities)

SOFTER TO CUT-

They can be cut with a knife

Once they are cut, they're shiny, but they go dull as they react with air and a layer of oxide forms on the outside

(This is why they are stored in oil) :)

LOWER MELTING AND BOILING POINTS-

The alkali have low melting and boiling points (for metals)

Lithium - melts at 180C and boils at 1330C

Caesium melts at 29C and boils at 670C

OTHERS-

Alkali metals are very reactive

They have one outer electron

They form 1⁺ ions.

ALKALI metals always form white ionic compounds - but dissolved in water they're colourless