Question | Answer |
EN is..... | The measure of attraction an atom has for a pair of bonding electrons |
IE is... | the minimium energy needed to remove an electron from an atom or ion in the gaseous state |
AR is... | half the distance between the bonded nuclei |
EN going across the periodic table... | Increases. |
EN across the periodic table why... | becasue of the increasing number of protons so there is an increasing attration for electrons |
IE going across the periodic table... | Increases |
IE across the periodic table why... | becaue of the increasing attraction for electrons which means more energy is requied to remove them |
AR going across the periodic table... | Decreases |
AR across the periodic table why... | increasing attraction for electrons pulls the valance shell closer to the nucleus |
EN going down the periodic table... | decreases |
AR going down the periodic table why... | decreasing attraction for electrons so valance shell is further away from nucleus |
EN going down the periodic table why... | increasing sheilding so there is a decrease in the attraction for electrons |
IE going down the periodic table... | decreases |
IE going down the periodic table why... | decreasing attraction for electrons so need less energy to remove them |
AR going down the periodic table... | increases |
Cations are what electrons | lost |
anions are what electrons | gained |
IR of positive ion | Fewer electrons are attracted more strongly to nucleus so IR is smaller than atom |
IR of negitive ion | More electrons create more repultion betweeen elctrons so IR is bigger than atom |
Pure covalent bond EN | 0-0.5 |
Polar covalent bond EN | 0.6-1.5 |
Ionic bond EN | 1.6+ |
Forming anions | electrons are added into orbitals of increasing energy |
Forming Cations | electrons are removed from 4s before 3d |
[Ar] | 1s2,2s2,2p6,3s2,3p6 |
Transition metals-Form complex ions | Central metal ion surrounded by ligands. Vacant 3d orbitals on t-metal ions accept these loan bonds |
Transition metals-Form coloured compounds | Electrons in the incomplete 3d orbital absorb specific wave lengths of light energy. The colour seen is the light energy not absorbed |
Transition metals-Make good catalysts | Vacant orbitals accept electron pairs from molecules. This strains the bonds in the molecules, encouraging reactions to occur |
Lower oxidation states are | monatomic ions |
Higher oxidation states | polyatomic ions |
| T metals lose 4s electrons and then a varying number of unpaired 3d electrons to give varying oxidation states |
2 Linear | 2,180, symmetrical |
Trigonal planar | 3, 120, symmetrical |
3 Angular bent | 3, 120, asymmetrical |
Tetrahedral | 4, 109, symmetrical |
Trigonal pyramidal | 4, 107, asymmetrical |
4 Angular bent | 4,104.5, asymmetrical |
Linear | 4,109, asymmetrical |
Trigonal bipyramidal | 5, 90, 120, symmetrical |
Seesaw | 5, 90, 120, asymmetrical |
T-shaped | 5, 90, 120, asymmetrical |
5 Linear | 5, 90, 120, symmetrical |
Octahedral | 6, 90, symmetrical |
Square-based pyramid | 6, 90, asymmetrical |
Square planar | 6, 90, asymmetrical |
Polar bond | unequally shared electrons between 2 atoms due to different EN |
Polar molecule | has an uneven spread of charge |
Non-polar bond | equally shared electrons between 2 identical atoms due to same EN |
Non-polar molecule | even spread of charge |
Intermolecular forces | forces within molecules or between ions |
Examples of intermolecular forces | covalent bonds, ionic bonds |
Covalent bonds | a strong attraction between atomic nuclei and shared pair of electrons. |
Stronger covalent bonds | caused by more electrons being involved |
Ionic bonding | strong EN attraction between cation and anion |
Stronger ionic bonds | caused by higher charges |