The Periodic Table Flashcards
Groups
Vertical column
Periods
Horizontal rows
Trend of ionisation energy
Generally increases as you go across a period as nuclear charges increase
- there is a decrease between group 2 and 3 as group 3’s outer shell is partially shielded by s electrons
Trend in electronegativity ?
- increases across a period because there is an increase in nuclear charge, but the bonding electrons are always
shielded by the same inner electrons.
Reactivity in Group 2
increased shielding as you go down the group making it easier to loose outer electrons because of a weaker nuclear charge.
Reactivity increases as you go down the group
Group 2 reaction with water
Reacts with water in a redox reaction to produce metal hydroxide and hydrogen
Mg + 2H20 = Mg(OH)2 + H2
Group 2 reaction with oxygen
- produces simple oxides
- as group 2 have an oxidation number of +2 it balances with the -2 in oxygen
What element is an exception in group 2 when reacting with oxygen
- Barium
- The oxygen ion has an oxidation number of -1
Ba + O2 = BaO2
Solubility of group 2 hydroxides
solubility increases down the group
- magnesium hydroxide = least
Group 2 reactions with sulfate
- produce metal sulfates
- decrease in solubility down the group
Group 2 flame test colours
Lithium = Crimson
Sodium = Yellow
Potassium = Lilac
Magnesium = No colour
Strontium = Orange
Calcium = Orange- Red
Barium = Pale green
Thermal stability of Group 2 carbonates
- Undergo thermal decomposition, require higher temperatures as you go down the group
- This is because thermal stability increases as you go down the group
MgCO3 = MgO + O2
Group 7 Elements
- highly reactive non-metals
- reactivity decreases down the group
Group 7 reaction with metals
- produce salts such a sodium chloride
Volatility of Group 7
- ## decreases down group 7
