deck_17051147 Flashcards
How are groups arranged on the P.T.?
They go down
Group 1
Alkali Metals
Group 2
Alkali Earth Metals
Groups 3-12
Transition Metals
Group 17
Halogens
Group 18
Noble Gases
How are periods arranged on the P.T?
They go across left to right
What do periods correspond with?
The number of Principle Energy Levels where valence electrons are located
Where are Metals located?
Left of Staircase
What do Metals form?
Cations
Description of metals
Malleable, ductile, good conductors
Where are nonmetals located?
Right of the staircase
What do nonmetals form?
Anions
Description of nonmetals
Brittle, dull, non-conductors
Locations of metalloids
Touch the staircase
What are the metalloids?
B, Si, Ge, As, Sb, Te
Nuclear Charge
Represented by atomic number and increases by one through each successive element
The outer electrons determine what?
Many physical and chemical properties of an element
What prevents the valence electrons from experiencing the full nuclear charge?
Repulsion and Shielding due to the inner electrons
As you go across period…
- Same amount of shielding
- Greater nuclear charge
More effective nuclear charge
As you go down group…
- Same effective nuclear charge
- Charge increases by 8
- Shielding increases by 8
Atomic Radius
Half the distance between neighboring atoms
Why does atomic radius increase down a group?
Greater numbers of P.E.L.’s as seen by period number
Why does atomic radius decrease across a period?
Same number of P.E.L.’s, greater nuclear charge
Cations are ___ than its atom
Smaller
Anions are ___ than its atom
Larger
Isoelectronic
The same electronic configuration
Cations have a…
Greater nuclear charge which pulls electrons closer, have a smaller radius
Anions have a…
Smaller nuclear charge, cannot pull electrons as close, larger radius
Electron Affinity
A measure in the charge in energy when one mole of its electrons are added to one mole of gaseous atoms to form gaseous ions; exothermic process
Becomes endothermic when adding a second electron
Electronegativity
A measure of an element’s attraction for one electron in a covalent bond
Electronegativity increases…
Across a period
Electronegativity decreases…
Down a group
The melting point of metals…
Increases as the number of valence electrons increases
Metalloids have…
Very high melting points and strong bonds due to being covalent structures
The melting point of nonmetals…
Are low due to weak intermolecular forces
The melting point of Noble Gases…
Are very low due to very weak intermolecular forces and being monatomic
Chemical properties of metals
-More reactive as you go down groups
-React by losing electrons
-Bigger, easier to lose electrons
Metal Oxides with Acids
Form a salt and water
Neutralization reaction, the metal cation bonds with the acidic anion to form a salt, the leftover H and O form water
Nonmetal Oxides with Bases (Alkali)
Form a salt and water
Neutralization reaction, shows that nonmetal Oxides are acidic in nature
Group 17 Reactivity
Most reactive at the top (F)
Properties of Fluorine
Yellow gas
Properties of Chlorine
Yellow/green gas
Properties of Bromine
Dark Red liquid
Properties of Iodine
Purple Solid
Displacement reaction
A more reactive halogen will be in compound form, less reactive alone
Nonmetal Oxides in water
Bonds together, forms an acid
Amphoteric Oxide (Al2O3)
Can act as both an acid and base (Lewis)
What two Nonmetal Oxides do not react with water?
SiO2 and CO
Properties of Transition Metals
- Variable oxidation states
- Incomplete d sublevel as atom or as positive ion
- Catalytic and magnetic properties
- Form complex ions with ligands
- Colored compounds
How is Zinc not a Transition Metal
It always has a complete d sublevel, is always colorless and only has one oxidation state
All Transition Metals can form what two oxidation states?
+2 and +3
From Sc to Cr, what oxidation state is the most common?
+3
The +2 oxidation state is most common where?
After Mn due to a greater nuclear charge making it harder to lose more than two electrons
Where and what is the maximum oxidation state?
At Mn, highest is +7
Trend for oxidation states
Oxidation states increase by one up to Mn, where they decrease by one after
What two metals have the highest oxidation states and are the best oxidizing agents?
Mn +7 and Cr +6
What do Transition Metals do as catalysts?
Increase the rate of reaction and provide an alternate pathway
Homogeneous catalyst
A catalyst in the same phase as the reactant(s)
Medical uses of Transition Metals
- Fe +2 heme in blooded to transport oxygen
- Co +3 in vitamin B12
Heterogeneous Catalyst
A catalyst in a different phase than the reactant(s)
Catalyst Converter
(Pd/Pt catalysts) Converts CO and NO into CO2 and N2
2CO + 2NO = 2CO2 and N2
Haber Process
(Fe catalyst) The production of ammonia from its elements
N2 + 3H2 = 2NH3
Contact Process
(V2O5 Vanadium V Oxide Catalyst) Production of sulfuric acid
2SO2 + O2 = 2SO3
Hydrogenation
(Ni catalyst) Converting unsaturated hydrocarbons into saturated hydrocarbons
C2H4 + H2 = C2H6
Decomposition of Hydrogen Peroxide
(MnO2 catalyst) 2H2O2 = 2H2O + O2
Magnetic properties of Transition metals
How they behave when introduced to a magnetic field
Paramagnetic
Contains unpaired electrons
-Will be pulled into a magnetic field
-Do not retain magnetic properties
-More unpaired electrons, more attraction
Diamagnetic
Contains paired electrons
-Weakly repelled by magnetic properties after field is removed
Ferromagnetic
Contain unpaired electrons that align parallel to each other in domains
-Retain magnetic properties when magnetic field is removed (Iron, Cobalt, Nickel)
Complex Ion
Because of their small size, d block ions act as Lewis acids and attract species that are electron rich (ligands)
Ligands
Species with lone pair(s) of electrons that form coordinate covalent bonds with a central metal ion. Ligands are Lewis bases
Spectrochemical series
I - < Br - < S -2 < F - < OH - < SCN- < NH3 < CO = CN -
Weakest -> strongest
Stronger = more splitting
Monodetant ligands
Form one coordinate covalent bond using one lone pair of electrons
*If the ligand is neutral, the charge of the central ion is the same as the complex ion
*The number of coordinate covalent bonds from the ligand to the central ion is the coordination number
Polydentant Ligands
Contain more than one pair of lone electrons and can form two or more coordinate covalent bonds to the central ion
Bidentant Ligands
Can form two coordinate covalent bonds (Oxalate ion C2O4 -2)
Ethylenediamine
H2NCH2CH2NH2
Hexadentate ligand
Has six atoms with lone pairs of electrons (EDTA -4)
Chelate
Two or more separate coordinate covalent bonds between ligand and central atom
Oxidization rules
- Compounds sum to zero
- Ions sum out to their charge (NO3-)
- Lone elements = 0
- Group 1 metals = +1
- Group 2 metals = +2
- Oxygen is almost always -2, unless peroxide or with F-2
- Hydrogen is +1 unless with metal -1
- Fluorine is always -1
Oxidation states vs oxidation numbers
Oxidation states: (+) or (-) in front
Oxidation numbers: Roman numerals
Color of Transition Metals
-Related to presence of partially filled d orbitals
-The color is determined by the color of light it absorbs and which color it transmits or reflects (Opposite color on the color wheel)
Degenerate
A free ion, the d orbitals are all of equal energy
Location of the 5 d orbitals
3 between the axis
2 along the axis
Splitting
When a ligand comes in, its lone electrons repell the 2 orbitals along the axis, causing them to split, anything that changes the splitting changes the color
Identity of central metal ion
-Larger metals provide greater splitting
-A greater nuclear charge will cause a greater electrostatic attraction to the ligand and result in more splitting
More energy = more splitting
Oxidation state of metal ion
As oxidation state increases for the same metal, the splitting of the d orbitals also increases
Geometry of Complex ion
Octahedrall (6) > Tetrahedral (4) > Linear (2)
Identity of ligand
Stronger ligand = greater splitting
(Cu(H2O)6) vs [Cu(NH3)4(H2O)2]
When some of the water ligands are replaced by ammonia the splitting of the d orbital increases. The new complex Ion will absorb more energy and light with decreasing wavelength.
