Chemistry of the Elements
Terms in this set (289)
Phase (of Matter)
Physical state of matter - Physically distinct as a homogenous part of a system
How are phases of matter determined?
Properties of each phase are determined by kinetic and potential energy of particles
How does kinetic energy effect particles?
Kinetic energy causes movement thus dissociates and disperses particles away from one another
How does potential energy effect particles?
Potential energy forms attractive forces and draws the particles together
Intramolecular Forces (Bonding)
Bonding forces within a molecule
Intermolecular Forces (Non-Bonding)
Forces that are found in-between two separate molecules
Intramolecular Forces and Chemical Behavior
Chemical behavior is the same between the phases of matter [because same constituent particle is present]
Intermolecular Forces and Physical Behavior
Physical behavior differ because the strength of the forces in the two molecules differ from one another
Gas Forces of Attraction
Attractive forces are weak (in relativity to kinetic energy) - Particles are far apart and there is no fixed shape or volume
Liquid Forces of Attraction
Attractive forces are stronger because the particles have less kinetic energy - The particles can flow and change (But have a fixed volume)
Solid Forces of Attraction
Attraction dominate motion - Particles are fixed in place relative to each other (There is no fixed shape or volume)
Conforms to shape and volume of container, has high compressibility, and high flow ability
Conforms to shape of container, has volume by surface, very low compressibility, and moderate flow ability
Maintains its own shape and volume, little to no compressibility, and almost zero flow ability
Liquid to gas
Gas to liquid
Liquid to solid
Melting / Fusion
Solid to liquid
Solid to gas
Gas to solid
Heat within a Phase
In a phase heat is accompanied by a change in temperature
Heat within a Phase Change
During a phase change heat flow is constant
Equation for Heat in a Phase
q = amount x heat capacity x deltaT
Equation for Heat in Phase Change
q = amount x deltaH of phase change
Molecules are entering and leaving the liquid at the same rate (in a closed flask)
Pressure exerted by the vapor on the liquid (increases until equilibrium) - At equilibrium vapor pressure holds constant
Factors of Vapor Pressure
Temperature and intermolecular forces
Temperature and Vapor Pressure
As temperature increases, vapor pressure increases - Fraction of molecules with enough energy to energy vapor phase grows
Intermolecular Forces and Vapor Pressure
As intermolecular forces weaken, vapor pressure increases - Easier for particles to to enter the vapor phase
What is the Clausius-Clapeyron equation used for?
Used to estimate the vapor pressure at another temperature (Relationship between the two is a not a linear line)
A liquid's temperature at which the vapor pressure equals the external pressure
Normal Boiling Point
The boiling point observed at standard atmospheric pressure (760 atm)
How does external pressure effect boiling point?
As external pressure of a liquid increases its boiling point increases
Graphic representation of the stabilities of physical states of a substance - As a function of temperature and pressure
What are equilibrium lines?
Represent phase changes between solids/liquids, liquids/gases, and gases/solids (Under specific conditions)
Nature of Intermolecular Forces
Intermolecular forces arise from attraction between molecules with partial charges (changes?) - Between ions and molecules
How do intermolecular and intramolecular forces differ?
Intermolecular forces between molecules - Intramolecular forces within a molecule
Basically ionic bonding
Interactions between an ion and a partial charge of a molecule with a permanent dipole
Attractive forces in-between polar molecules
Type of dipole-dipole interaction that requires a Hydrogen atom covalently bonded with strong electronegativity
A momentary separation of charges in an atom (uneven electrons)
Dispersion Interactions (Hydrophobic Force)
Caused by temporary dipoles
How does an ion-ion interaction occur?
Attractive force increases as charge on the ion increases and decreases as ionic radius increases
Energy of interaction is directly proportional to the charge of the ions (Inversely to the distance between them)
Coulomb's Law Equation
A hydrogen atom is covalently bonded to flourine, nitrogen, or oxygen and the fluorine, nitrogen, or oxygen atom has at least one lone pari of electrons
Intermolecular Hydrogen Bonding
An attraction between a hydrogen atom of a molecule and a lone pair of the nitrogen, fluorine, or oxygen atom of another molecule
Polarizability or Induced Dipoles
The proximity of an electric field can induce distortion in an electron cloud of an atom
How does an atom being non-polar effect induced dipoles?
Non-polar atoms induce a temporary dipole moment
How does an atom being polar effect indued dipoles?
Polar atoms enhance existing dipoles
The ease as which a particles electron cloud is distorted
How do smaller particles effect polarizability?
Smaller particles are less polarizable because the electrons are held tighter together
How does atomic size effect polarizability?
Polarizability increases down group as atomic size increases
How do cations and anions effect polarizability?
Cations are more polarizable than the parent atom - Anions are less polarizable than the parent atom
Dispersion Forces (Non-Polar)
Atoms that are far apart don't influence each other - When the atoms are close the instantaneous dipole in one atom induces a dipole in the other
Dispersion Forces (Polar)
When induced dipole results in an attraction between atoms (Dispersion forces exist between all particles) - More polarizable results in a greater dispersion force
Depends on the relative strength of solute-solvent interactions compared to the solute-soluble or the solvent-solvent
When are ionic and polar solutes soluble?
Soluble with polar solvents
When are non-polar solutes soluble?
Soluble with non polar solvents
Interaction repels water (Diminishing water solubility)
Interaction attracts water (Promotes water solubility)
Interacting Particles + Ions + Ion / Polar Molecule
Interacting Particles + Ions + Ions Only
Interacting Particles + No Ions + Non-Polar Only
Interacting Particles + No Ions + Polar / Non-Polar
Interacting Particles + No Ions + Polar Only
Interacting Particles + No Ions + Polar Only + H bonded to N, O, or F
Determining the ages of certain objects using measurements of relative Carbon 14 and Carbon 12 amounts
Why is Carbon 12 and Carbon 14 used for radiosoptoci dating?
Carbon 14 and carbon 12 remain constant for all living organisms - Once dead Carbon 14 decays and forms Nitrogen 14 at a very predictable rate
What elements are used for the radioisotopic dating of rocks?
The ratios of Potassium 40 and Argon 40 are used for rocks
Half Life Equation
t = (1/K)ln(A0/At)
The induced conversion of the nucleus of one element into the nucleus of another
How is nuclear transmission achieved?
Nuclear transmission is achieved by high energy bombardments of nuclei in a particle accelerator
Simple Written Form of Nuclear Transmission
Reactant nucleus (particle in, particle out) product nucleus
How does it WORK SIMPLE FORM NUCLEAR TRANMISSION
How does radiation effect ionization?
Radiation causes ionization when colliding with surround matter - It produces cation and a free electron
Are directly related to energy of incoming ionization radiation
How does radiation effect tissue?
Radiation has destructive effect on living tissue - Depending on half life, biological behavior, and radiation type
Units of Radiation
The gray, the rad, the rem
The S.I. unit for energy absorption (1 Gy = 1 J absorbed per kg of body tissue)
.1 J/kg or .01 Gy (More commonly used )
Unit of radiation dosage is equal to tissue damage in a human (Number rem equals number of rad x relative bio effectiveness)
Heaviest particle and the least penetrating - Stopped with paper
Slightly lighter and can penetrate further - Stopped with plastic
Penetrating the most - Stopped with lead or concrete
Inversely related to mass, charge, and energy of emission - Problematic because it creates a free radical
Molecular and atomic species with 1+ unpaired electrons - Extremely unstable and reactives
A source of ionizing radiation - Increases with altitude
The product of Uranium or Thorium decay - Accounts for 15% of all lung cancer deaths
A source of ionizing radiation - Present in carbon dioxide
A source of ionizing radiation - Present in water and some food sources
Small amount of radioactive isotope mixed with a stable isotope that undergoes the same chemical reactions
What is a tracer used for?
Tracers are used to study reaction paths, track physiological functions, trace material, diagnose medical conditions, identify substance components
Are isotopes similar in chemical or physical behavior?
Isotopes are similar in chemical and physical behavior
Other Radiation Uses
Insect control, radiation therapy, destruction of microbes (increases shelf food life), and power of spacecraft interments
Woman of nuclear chemistry - Discovered radioactivity
When was radioactivity discovered?
1898 (Marie Curie)
Woman of nuclear chemistry - Discovered artificial radioactivity and identified the neuron
When was artificial radioactivity discovered?
Woman of nuclear chemistry - Discovered and explained nuclear fission
When was nuclear fission discovered?
Splitting of a large nucleus into smaller nuclei - Done using bombardment to start the process
What is the process of nuclear fission?
Nuclear fission releases lots of energy and generates more high energy neutrons - Results in more fusion
Is nuclear fission self-sustaining?
Nuclear fission is a self-sustaining chain reaction
Mass requires to achieve a self-sustaining reaction
Nuclear Power Plant
The harnessing of energy from a nuclear fission into other forms of energy
How does a nuclear power plant work?
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Very simple structure (Nucleus equals a single positive charge and has one electron) - Most abundant element in universe (Exists as a diatomic gas)
What are the properties of hydrogen?
Colorless, oderless, low melting and boiling point
How is hydrogen similar to group 1A?
Hydrogen has electron configuration of ns1, single valence electron, +1 oxidation state
How does hydrogen differ from the rest of group 1A?
Hydrogen shares electron with non-metals (doesn't transfer), and has higher ionization energy (due to smaller size)
How is hydrogen similar to the group 4A?
Hydrogen has a 1/2 filled valance level, similar in ionization levels, electron affinity, electronegativity, and bond energies
How is hydrogen similar to group 7A?
Hydrogen exists as a diatomic molecule, only needs one electron to fill outer shell
How is hydrogen different from group 7A?
Hydrogen has a much lower electronegativity, it lacks 3 valence lone electron pairs, hydrogen ions are rare and reactive
Ionic (Saltlike) Hydrides
Hydrogen + Very reactive metals
Covalent (Molecular) Hydrides
Hydrogen + Non metals (That react together)
Formed by many transition metals (which diatomic hydrogen molecules and hydrogen atoms occupy holes in the crystal structure of the metal)
2 Atoms of hydrogen are combined in steps to create helium
How much of hydrogen atoms combining into helium atoms account for the sun's energy?
Where do elements come from?
In the interior of stars ??
How many elements have occurred naturally?
90 Elements occurred naturally
How do nuclear and chemical reactions differ in energy?
Energy changes in nuclear reactions are MUCH greater then chemical reactions
What are nuclear reactions?
Nuclear reactions are changes in energy
The Mass Defect
The mass of an atom is is always less then the sum of other masses of its component particles
What is the exception to the mass defect?
Nuclear Binding Energy
The amount of energy released when nucleus forms
Holds the mass of an atom
Mass Defect of Fusion of Hydrogen
Compromised of neutrons and protons - The nucleus compromises
The total number of nucleons in a nucleus
An atom with a particular number of protons and neutrons
One of two or more nuclides (Have the equal number of protons, but do not have and equal number of neutrons) - Different mass number
Notation of a Nucleus
X = Element
A = Mass number
Z = Protons in particles
Chemical versus Nuclear Reactions
Types of Nuclear Reactions
Nuclear fusion, nuclear fission, and nuclear decay
Nuclear Fusion Process
Two lighter nuclei colliding to form a heavier nucleus
Nuclear Fission Process
A heavier nuclei breaking up to form two lighter nuclei
Nuclear Decay Process
When a nucleus decomposes to form a different (more stable nucleus)
Why do chemical and nuclear reactions take place?
Chemical and nuclear reactions take place to be more stable
Daughter Nuclide (of Low Energy)
A result of nuclide decay - The excess energy is carried off by emitted radiation and the recoiling nucleus of daughter nuclide
How is nuclear stability determined?
The excess energy is carried off by emitted radiation and the recoiling nucleus of daughter nuclide
Bond of Stability
Produced by a plot (Number of neutrons versus number of protons for stable nuclides) - Gradually curves above the line N = Z
When are lighter nuclides stable?
Lighter nuclides are stable when N = Z
When are nuclides unstable?
All nuclides are unstable when Z is greater than 83
How does the increase of Z effect stable or unstable nuclei?
As Z increases - N/Z for stable nuclei gradually increases
Involves the loss of an alpha particle from the nucleus (A decreases by 4, Z decreases by 2)
Involves the ejection of a beta particle from the nucleus (A decreases by 0, Z increases by 1)
What is the most common form of decay for a heavy nucleus?
Most common form of decay for a heavy or unstable nucleus
Emission of a positron from the nucleus (Z decreases by 1)
What is the antiparticle of the electron?
Occurs when the nucleus interacts with an electron in a low atomic energy level - A proton is transformed into a neutron (Z decreases by 1)
Gamma (y) Emission
Involves radiation of high energy (y) photons - No change in A or Z since y rays have no mass and change (Occurs together with other forms or radioactive decay, several y photons of different energies can be emitted from an excited nucleus as it returns to the ground state)
Detects radioactive emission as they ionize a gas - Produces a free electron and a gaseous cation (Attracted to electrons and produce an electric current)
Detects radioactive emissions by their ability to excite atoms and cause them to emit light
How do scintillation counter works?
Radioactive particles strikes a light emitting substance which photons - Photons strike a cathode and produce units of an electric current
SI unit of radioactivity (One disintegration per second)
A more commonly used unit (1 Ci equals 3.7x10^10 d/s)
Relationship between radioactive decay and number of nuclei
The rate of radioactive decay (A) is proportional to the number of nuclei present
What is the rate of radioactive decay?
At a characteristic rate (regardless of substance) - Decay follows the first order kinetics rate (The rate constant is K)
The rate constant K
What does a larger K value entail?
A larger K value results in higher activity of the substance
The time taken for half the nuclei in a sample to decay
How does the mass of the daughter and the mass of the nucleide interact with one another?
As the mass of the parent nucleide decreases, daughter mass increases
How does activity change over the course of a half life?
Activity is halved with each succeeding half life
Characterized by gain or less of electrons
Loss of electrons - Involves diatomic oxygen
Gains of electrons - Involves diatomic oxygen loss or diatomic hydrogen gain
Oxidation Number for Group 1A
Oxidation Number of Group 2A
Oxidation Number of Hydrogen
+1 with non-metals, -1 with metals and boron
Oxidation Number of Oxygen
-2 in all compounds - With the exception of F and peroxides
Oxidation of Oxygen with Fluorine and Peroxides
Oxidation Number in Group 7A
-1 with metals, non-mates, and halogens
One reactant loses an electron (Reduction agent is oxidized, oxidation number is increases)
One reactant gains an electrons (Oxidizing agent is reduced, oxidation number decreased)
Uses a spontaneous redox reaction (deltaG < 0) to generate electrical symmetry - System does work on surroundings
Uses electrical energy to drive a non spontaneous reaction (deltaG > 0) - Surrounding does work on system
Electrode which oxidation occurs
Electrode which reduction occurs
Cells in Voltaic Cells
Cells are constructed by two electrodes in a electrolyte solution
Oxidation 1/2 Reaction
Reduction 1/2 Reaction
Simple salt bridge completes the electrical signal and allows ions to for through both half cells - Positive flow to cathode
Which direction do electrons flow?
Electrons flow from the anode to the cathode
Drawing of Voltaic Cell
Anode goes on the left, cathode goes no the right
Solid Element I Aqueous Cation II Aqueous Anion I Solid Element
What does the single line in the notation of an oxidation reaction mean?
A boundary between the solid and aqueous elements
What does the double line in the notation of an oxidation reaction mean?
Demonstrates a physical separation
What does the drawing of the ________ look like?
Voltaic cell converts deltaG of a spontaneous redox reaction into the kinetic energy of electrons - Depends on the difference in electrical potential between the two electrodes
When is the cell spontaneous?
Ecell is greater then 0 when spontaneous
Standard Electrode Potential (E half cell)
Potential of a 1/2 given reaction when all components equals standard state - Refers to S.E.P. written as reduction
What does the standard cell potential depend on?
Standard cell potential deeds on difference between abilities of the two electrodes to act as oxidizing agents
Energy of Cell
Energy cathode (Reduction) - Energy anode (Oxidation)
What does a positive energy cell value entail?
Readily reactant acts as an oxidation agent
What does a negative energy cell value entail?
Readily products acts as oxidation agent
How do the energy cell values demonstrate a cell's ability to oxidize?
The energy of a cell's value reflect the cells ability to oxidize
What does a positive cell energy entail?
A positive cell energy of a metal entails a more active metal
Does a cathode have lower or higher redox potential?
A cathode has higher redox potential
Of the higher or lower metal which is the cathode and which is the anode?
The higher metal is the cathode, the lower metal is the anion
deltaG < 0 and Ecell > 0
-nFEcell (n = number of moles, F = faraday constant, cell energy potential)
What is the situation when Q<1?
Reactant > Product, lnQ < 0, so Ecell > Ecell standard
What is the situation when Q>1?
Reactant < Product, lnQ > 0, so Ecell < Ecell standard
What is the situation when Q=1?
lnQ=0, Ecell = Ecell standard
Equation for finding the Ecell of a random cell?
Ecell = Ecell standard - (.0592/n)(logQ)
Technology of metals and is concerned with their extraction and utilization
Uses heat to obtain the metal
Employs an electromechanical step to obtain the metal
Relies on metals aqueos solution chemistry
Steps of Extraction of the Element
3. Mineral to compound
4. Conversion compound to metals
6. Alloying the element
Magnetic attraction, leaching, floatation, cyclone separation
Mineral to Compound
- Converted to oxides because oxides can easily be reduced
Conversion to Compound
Reducing the metal out of the compound
Purifying the element through zone refining, electrorefining, or distillation
Alloying the Element
Alloying the element - Most element metals aren't 100% one metal
Simple Cubic (Unit Cell)
A particle in each of corners of the cube - 1 atom per unit
Face Centered Cubic (Unit Cell)
A unit cell in which a particle occurs at each corner and in the center of each face of a cube - 4 atoms per unit
What is the coordination number of a face centered cubic unit cell?
What is the coordination number of a simple cubic unit cell?
Body Centered Cubic Unit Cell
A unit cell in which a particle lies at each corner and in the center of a cube - 2 atoms per unit
How much percent does the simple cubic account for in an atom?
How much percent does the face centered cubic account for in an atom?
Simple Cubic (A Equation)
2R = A
Body Centered Cubic (A Equation)
A = 4R / √3
Face Centered Cubic (A Equation)
A = √8R
Atomic (Crystalline Solids)
Solids consist of individual atoms (held together only by dispersion forces)
Molecular (Crystalline Solids)
Solids consist of individual molecules (held together by various combination of bonds)
Ionic (Crystalline Solids)
Solids consist of a regular array of cation sand anions
Metallic (Crystalline Solids)
Solids exhibits organized crystal structure
Network Covalent (Crystalline Solids)
Solids consist of atoms covalently bonded together in a 3D network
Metal - There is no energy gap between the conduction band and the valence bond
A material that does not allow heat or electrons to move through it easily - Large energy gap between conduction band and valence band (non-metals)
Metalloid - Small energy gap between the conduction band and valence band
Has an energy gap (Conductivity at lower room temperatures)
Doping Silicon (PN Doping)
Adds an electron - Bridging gap and increasing the conductivity (P-N type doping)
Doping Silicon (Gallium P Doping)
Removes an electron - Introduces positive ions (Gallium P type doping)
Any solid compromising an inorganic metalloid
Do liquid crystals align in a pattern?
No liquid crystals align in different patterns
Large molecular (composed of repeating segments) - Don't have a set boundary i.e. no layers or limits and not arranged like crystals
Elastic polymer (Rubber)
Nanoparticles of semiconducting materials (GaAs or GaSe)
What do smaller quantum dots mean?
Smaller dots mean a shorter wavelength - All dots are smaller than 10 nm
Nanoparticles of magnetic dispersed in a viscous fluid suspended between poles of a magnet - Used in hard drives (High spinning but low friction)
Periodic table creator
When was the periodic table created?
Periodic repetition of chemical and physical properties of the elements within a group
Effective Nuclear Charge
Zeff = Z - S (S is number of inner electrons, Z is the number of protons)
What are the Zeff trends through the periodic table?
Increases up and across (to the right) through the table
Size of Atoms trends
Increases down and to the left of the periodic table
What is the exception to the size of the atom trends?
Row six (The lanthanide contraction) - Due to lanthanides having f orbitals there is poor shielding of f orbitals
How do the lanthanide contraction effect the trend of atomic size?
There is an increase, decrease, then increases again through the lanthanides
Ionization Energy Trends
Increases up and across to the right of the table - Exception when going from transition metals to column 13
Ionization Energy Trend Exceptions
Be --> B and N --> O
Metallic Behavior Trends
Increases down and to the left of the table (Same as atomic size)
In general increases to flourine and decreases down a column - Transition elements are more or less constant
Exceptions to Electronegativity Trends
Columns 13 and 14 (There is increase down the column)
Non Metal Line
Separates metals and non-metals
Chemistry of the 2nd row elements is significantly different from other members in their group - The element in the third group is a better representation of the group
Why is the uniqueness principle in affect?
The second row has a smaller size (due to more Zeff charge and electron electron repulsion), there is unavailability of d orbitals, and has an enhanced ability to form pi bonds
Diagonal relationship between the first member of a group and the second member of the next group
What are the similarities found in the diagonal effect?
Radii size, charge density, and electronegativity
Are group or diagonal relationships more important?
Group relationships are more influential
Inert Pair Effect
VAlence electrons of metallic elements in ns^2 (particularly 5s^2 and 6s^2) pairs follow the 2nd and 3rd row transition metals are less reactive then expected
What is an example of the inert pair effect?
The 5s^2 and 6s^@ pairs form compounds with oxidation states of 2 (Less then expected group valence)
What does higher vapor pressure mean for intermolecular force?
High vapor pressure entails a weaker intermolecular force
What does a low boiling point mean for intermolecular forces?
Lower boiling point means there are weaker intermolecular forces present
What does high viscosity mean for intermolecular bonds?
A high viscosity means a stronger intermolecular force
What makes a stable nuclide below Z= twenty?
A N/Z ratio of 1
What makes a stable nuclide above twenty?
The band of stability
What process is radioactive decay?
First order kinetics process (ln[Nt/N0] = kt)
How can an alpha particle be written in a nuclear equation?
4 = Z, 2 = A He