The Periodic Table Flashcards
A Group
Vertical column of elements with the same number of electrons in outer shell
Have fairly similar properties
Elements are arranged in
Order of atomic number
A period
Horizontal row
Same number of occupied shells
Do not have similar properties
Group one reactivity
Very reactive
Group 1 lose of gain
Lose 1 electron
Group 1 bonding
Soft Weak metallic bonding
e- per M+ ion
M+ ions in a sea of delocalised electrons
Low melting and boiling point
Low densities - first 3 alkali metal float on water
Ionic bonding
Metal and non-metal
Group 2 properties of compounds
Hard, brittle
High melting point
Don’t conduct electricity in solid state
Conduct electricity when liquid
Dissolve in water NOT in non polar solvents
Lithium reaction with water
Floats, fizzes, gets smaller, moves around, eventually disappears
Makes lithium hydroxide
Sodium reaction with water
Floats, fizzes, gets smaller, moves around, eventually disappears
Melts into silver ball
Potassium with water
Floats, fizzes, gets smaller, moves around, eventually disappears
Violent
Lilac flame
Halides, sulphates, nitrates and carbonates
Dissolve in water
Not in non polar solvents
Ionic compounds
Uses of group 1 elements and compounds
LiI batteries
KCl fertaliser
NaOH bleach/oven cleaner
NaCl salt preserves food
Group 1 gets
More reactive as go down
Lose electrons
++
Gain electrons
–
Group 2 properties
Less reactive - lose 2 electrons Metallic bonding M++ for every 2e- Lattice Higher melting point as attraction is stronger Hard
Reaction with steam forms
Oxide
Reaction with water forms
Hydroxide
Ca(OH)2
Hydrogen gas clings to Ca so less dense so floats.
Then hydrogen escapes into atmosphere so sinks.
Bobs up and down
Metal carbonate + heat
Metal oxide + carbon dioxide
Uses of group elements and compounds
Mg(OH)2 milk of magnesia neutralises excess acid in stomach
CaCO3 toothpaste