3. & 13. Periodicity Flashcards
Recommended names for groups 1-18
1: alkali metals
2: alkaline earth metals
15: pnictogens
16: chalcogens
17: halogens
18: noble gasses
Different atomic radii
Covalent radius: Rb = 1/2d
Non-binding radius: Rnb, also called van der Waals’ radius
Ionization energy, IE
the minimum energy required to remove 1 mol of electrons from a mol of a neutral gaseous atom in its ground-state (measured in kJ/mol)
The first ionization energy, IE1, is related to: X(g) –> X+(g) + e-
Increases across period and decreases down group
Electron affinity, Eea
The energy released when 1 mol of electrons is attached to 1 mol of neutral atoms or molecules in a neutral stage. This is the energy associated with the process: X(g) + e- –> X-(g)
Electronegativity
the relative attraction that an atom has for the shared pair of electrons in a covalent bond - direct relation to reactivity of non metals
Generally increases across period and decreases down groups
Metalloid
A metalloid is an element that has properties that are intermediate between those of metals and nonmetals. Metalloids can also be called semimetals. On the periodic table, the elements colored yellow, which generally border the stair-step line, are considered to be metalloids.
Amphoteric
can act both as an acid or base
Trend in first ionization energy in transition elements
While the the Fie increases across the period, it does so much less dramatically as the lost 3d electrons have been shielded by inner shells.
Some characteristics for d-block elements
● they have variable oxidation states (and are therefore often used as catalysts)
● compounds of transition elements and their ions are often coloured
● transition metals form complexes with ligands
● transition metals are often used as catalysts
● magnetic properties of transition metals depend on their oxidation states and coordination number.
Z_eff = Z - S
Nuclear charge effect on electron = nuclear charge - the charge shielded by the core electrons.
Atomic radii down a group and across period
Increased down groups, decrease across a period.
What light is absorbed when you see a colour?
The complimentary colour, when black, everything, white, nothing.
Name the 5 degenerate d orbitals
xy, xz. yz. z^2, x^2-y^2
What happens to degenerate d orbitals when a ligand is nearby (CFT)
According to Crystal Field Theory, the orbitals split into two groups: a higher E level (destabilized, e_g), a lower E level (stabilized, t_2g).
How does the Crystal Field Theory explain coloured complexes?
An electron is promoted from the stabilized, lower t_2g level, for which it needs energy which it will get from a visible photon, where the colour is absorbed and the complimentary is transmitted. This is known as d-to-d electronic transitions.
