Topic 4 - Inorganic Chemistry And The Periodic Table: Group 2 And 7 Flashcards
(37 cards)
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.
Group 7
Down the group boiling point…
Increases due to the increase in the number of electrons in the molecules causing the strength of the London forces to increase.
Group 7
Down the group electronegativity…
Decreases as the atoms get larger and the distance between the positive nucleus and the bonding electrons increases. Also shielding.
Colour and physical state of fluorine
Pale yellow gas
Colour and physical state of chlorine
Green gas
Colour and physical state of bromine
Brown liquid
Colour and physical state of iodine
Grey solid (which forms a violet vapour)
Group 7
Down the group reactivity decreases…
Because for a reaction to occur an electron is gained, and atoms with a smaller radius attract electrons better than larger atoms (Halogens are less oxidising as we go down the group).
Halogens will displace a halide from solution if…
Same with other halogens
The halide is lower in the periodic table (less reactive).
Halogens react with group 1 and 2 elements to form…
Metal halides
