3&13. Periodicity Flashcards Preview

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Flashcards in 3&13. Periodicity Deck (26)
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1
Q

Atomic radius

A

Radius of atom

2
Q

Ionic radius

A

Half the distance between two ions in a lattice that are barely touching.

3
Q

Electronegativity

A

The ability of an atom to attract the shared electrons in a covalent bond.

4
Q

Ionisation energy

A

The minimum energy required to remove the outermost electron in the gaseous state

5
Q

Melting and boiling points

A

The temperatures at which a substance changes state.

6
Q

Electron affinity

A

Minimum energy change when adding an electron to a gaseous atom.

7
Q

Trend in atomic radius across a period

A

Decreases

Increase in nuclear charge

8
Q

Trend in atomic radius down a group

A

Increases

More energy levels

9
Q

Trend in ionic radius across a period

A

Decreases until negative ions when it reaches maximum before falling.
Positive ions will get smaller than parent atom because there is a greater effective electric charge.
Negative ions will be larger as there is greater electron-electron repulsion and shielding.

10
Q

Trend in ionic radius down a group

A

Increases

More energy levels

11
Q

Trend in electronegativity across a period

A

Increases

Increased nuclear charge - greater force between nucleus and shared electrons

12
Q

Trend in electronegativity down a group

A

Decreases

Bond electrons further from nucleus

13
Q

Trend in ionisation energy across a period

A

Increases (generally)

Greater nuclear charge

14
Q

Trend in ionisation energy down a group

A

Decreases

More shielding and e-e repulsion

15
Q

Trend in melting and boiling points across a period

A

Rise across a period and reach maximum at group 4 then fall to min at group 0
Metals - larger positive charge and more delocalised electrons

Non-metals – in diatomic molecules v low but v high in giant covalent structures.

16
Q

Trend in melting and boiling points down a group

A

Group 1/2 – decreases
Non-metals - increase
More shielding – less attraction between nuclei and delocalised electrons
Larger atoms – greater intermolecular forces

17
Q

Trend in electron affinity across a period

A

Increases

Increased nuclear charge

18
Q

Trend in electron affinity down a group

A

Decreases

More shielding

19
Q

Transition metals must

A

o have variable oxidation states
o form complex ions with ligands
o have coloured compounds
o display catalytic and magnetic properties

20
Q

Complex ion

A

a species formed when when ligands bond to a central metal ion using coordinate bonds.

21
Q

Ligand

A

species with lone pairs of electrons that act as Lewis bases; they donate a pair of electrons to the central metal ion.

22
Q

 Monodentate ligand =

A

a ligand that forms only one coordinate bond with the ion.

23
Q

 Bidentate ligands =

A

a ligand that forms two coordinate bonds with the ion.

24
Q

 Polydentate ligand ).

A

a ligand that forms multiple coordinate bonds with the ion (e.g EDTA which forms 6

25
Q

 Homogenous catalyst =

A

a catalyst that is in the same physical state as the reactants.

26
Q

 Paramagnetism =

A

a form of magnetism whereby certain materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field.