Topic 4 - Inorganic Chemistry And The Periodic Table: Group 2 And 7 Flashcards
Group 2
As you go down the group, atomic radius…
Increases due to more shells and shielding
Group 2
As you go down the group, first ionisation energy… (5 points)
Decreases due to more shells, more shielding which results in a weaker attraction between the nucleus and outer electrons, increase in atomic radius so outer electron is further from nucleus, so less energy is needed to remove the outer electron
Group 2
These elements react with water to form…
Metal hydroxides
Group 2
Down the group reactivity with water…
Which element has no reaction with water?
Increases as atomic radius increases so the outer electrons are further from the nucleus making it easier to remove. There is also more shielding.
Beryllium
Group 2
How does magnesium react with water?
Mg reacts slowly with cold water but more vigorously with steam. This produces magnesium oxide (MgO) instead of hydroxide.
Group 2
The elements react with oxygen to form…
Bases/metal oxides. Group 2 oxides are white solids.
Group 2
These elements react with chlorine to form…
Metal chlorides
Group 2
Group 2 oxides react with water to form…
Bases/alkaline solutions
Group 2
Group 2 oxides and hydroxides can neutralise acids to form…
A salt and water
Group 2
Group 2 carbonates thermally decompose down into…
Metal oxides and carbon dioxide
Group 2
Group 2 nitrates thermally decompose down into…
Metal oxides, nitrogen dioxide and oxygen
Group 2
Thermal stability depends on…
The polarising power of the cation, which is determined by its charge density. Compounds containing cations that strongly polarise the anion (distort the anion electron cloud) are more easily decomposed.
Group 1 carbonates are more or less thermally stable than group 2 carbonates?
More because the group 1 elements have larger radii, so they are less polarising.
Which group 1 carbonate is able to thermally decompose?
Lithium because it is a small cation and polarises the carbonate ion sufficiently compared to the others that are bigger.
How do the different group 1 nitrates decompose?
Lithium is the only group 1 element that decomposes like group 2 nitrates as it forms lithium oxide, nitrogen dioxide and oxygen. Whereas the other elements form a metal nitrite and oxygen.
