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1) An electron shell of the atom may be thought of as an orbit followed by electrons around anatom nucleus. Because each shell can contain only a fixed number of electrons, each shell is associated with a particular range of electron energy, and thus each shell must fill completely before electrons can be added to an outer shell. The electrons in the outermost shell determine the chemical properties of the atom (seeValence shell)

Energy levels. The contrasts with classical particles, which can have any energy. These discrete values are called energy levels. The term is commonly used for the energy levels of electrons in atoms, ions, or molecules, which are bound by the electric field of the nucleus, but can also refer to energy levels of nuclei or vibrational or rotational energy levels in molecules. The energy spectrum of a system with such discrete energy levels is said to be quantized.

The wave nature of microparticles motion. The diffraction of particles can be understood only on the basis of quantum theory. Diffraction is a wave phenomenon; it is observed in the propagation of a variety of waves: the diffraction of light, sound waves, waves on the surface of a liquid, and so on. From the standpoint of classical physics, diffraction is impossible in the scattering of particles. Quantum mechanics has eliminated the absolute boundary between the wave and the particle. Particle-dualism, that is, the dual nature of microparticles, is the principal proposition of quantum mechanics, which describes the behavior of microentities.

The uncertainty principle. In quantum mechanics, the uncertainty principle is any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle known as complementary variables, such as position x and momentum p, can be known simultaneously.

The electron cloud. In chemistry and nuclear physics, the electron cloud is the only way to describe where electrons are when they rotate around the nucleus of an atom. The electron cloud modelis different from the older model by Niels Bohr. Bohr talked about electrons going around the nucleus in a fixed circle, the same way that planets go around the Sun. The electron cloud model says that we can't know exactly where an electron is, but the electrons are more likely to be in specific areas of an atom. It is the most modern and accepted form of the atom.

2) Electron configurations of the elements. Electron configurations of the neutral gaseous atoms in the ground state. Given by subshells in concise form, by subshells written out, and by number of electrons per shell. Electron configurations of elements beyond nobelium (element 102) are tentative and those beyond rutherfordium (element 104) are predicted. For example: 49 In indium : [Kr] 4d10 5s2 5p1

Hund's rule. The three rules of Hund:

1. For a given electron configuration, the term with maximum multiplicity has the lowest energy. The multiplicity is equal to 2S+1, where  is the total spin angular S.

2. For a given multiplicity, the term with the largest value of the total orbital angular momentum quantum number L has the lowest energy.

3. For a given term, in an atom with outermost subshell half-filled or less, the level with the lowest value of the total angular momentum quantum number J (for the operator J=L+S) lies lowest in energy. If the outermost shell is more than half-filled, the level with the highest value of J is lowest in energy.

Electron configurations of the main group elements.  We're finally ready to discuss the chemical properties of the simplest chemicals out there – we're finally ready to discuss the elements. Remember, you have learned that there were 118 different kinds of atoms, and that each was known as an element. And you have learned that atoms of different elements have different numbers of protons. Hydrogen has 1 proton (and 1 electron if it's neutral), helium has 2 protons (and 2 electrons, if it's neutral).

3) The periodic table. The periodic table is a table of the chemical elements in which the elements are arranged by order of atomic number in such a way that the periodic properties (chemical periodicity) of the elements are made clear. The standard form of the table includes periods (usually horizontal in the periodic table) and groups (usually vertical). Elements in groups have some similar properties to each other. 

Atomic properties and periodic trends. The electrons associated with atoms are found to have measurable properties which exhibit quantization. The electrons are normally found in quantized energy states of the lowest possible energy for the atom, called ground states. When comparing the properties of the chemical elements, recurring ('periodic') trends are apparent. This led to the creation of the periodic table as a useful way to display the elements and rationalize their behavior. When laid out in tabular form, many trends in properties can be observed to increase or decrease as one progresses along a row or column.

Atomic size. The first of these properties is the atomic size. You know that each atom has a nucleus inside and electrons zooming around outside the nucleus. It should seem reasonable that the size of an atom depends on how far away its outermost (valence) electrons are from the nucleus. If they are very close to the nucleus, the atom will be very small. If they are far away, the atom will be quite a bit larger. So the atomic size is determined by how much space the electrons take up.

Ionization energy. The ionization energy (IE) of an atom or molecule describes the minimum amount of energy required to remove an electron (to infinity) from the atom or molecule in the gaseous state. X + energy → X+ + e-The term ionization potential has been used in the past but is not recommended.

The units for ionization energy vary from discipline to discipline. In physics, the ionization energy is typically specified in electron volts (eV) and refers to the energy required to remove a single electron from a single atom or molecule.

Electron affinity. In chemistry and atomic physics, the electron affinity of an atom or molecule is defined as the amount of energy released when an electron is added to a neutral atom or molecule in the gaseous state to form a negative ion.

X + e → X + energy

4) Chemical bond formation. Valence bond (VB) theory is one of two basic theories, along with molecular orbital (MO) theory, that were developed to use the methods of quantum mechanics to explain chemical bonding. It focuses on how the atomic orbitals of the dissociated atoms combine to give individual chemical bonds when a molecule is formed. In contrast, molecular orbital theory has orbitals that cover the whole molecule.

Valence electrons. In chemistry, a valence electron is an electron that is associated with an atom, and that can participate in the formation of a chemical bond; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair. The presence of valence electrons can determine the element's chemical properties and whether it may bond with other elements: For a main group element, a valence electron can only be in the outermost electron shell. In a transition metal, a valence electron can also be in an inner shell.

The formation of a covalent bond in H2 molecule. The classic case of covalent bonding, the hydrogen molecule forms by the overlap of the wavefunctions of the electrons of the respective hydrogen atoms in an interaction which is characterized as an exchange interaction. The character of this bond is entirely different from the ionic bond which forms with sodium chloride, NaCl.

Properties of covalent bond.

Physical properties

Covalent compounds

States (at room temperature)

Solid, liquid, gas

Electrical conductivity

Usually none

Boiling point and Melting point

Varies, but usually lower than ionic compounds

Solubility in water

Varies, but usually lower than ionic compounds

Thermal conductivity

Usually low

5) Main concepts of chemical kinetics. Chemical kinetics, also known as reaction kinetics, is the study of rates of chemical processes. Chemical kinetics includes investigations of how different experimental conditions can influence the speed of a chemical reaction and yield information about the reaction's mechanism and transition states, as well as the construction of mathematical models that can describe the characteristics of a chemical reaction.

Simple and complex, homogeneous and heterogeneous reactions. homogeneous reaction,  any of a class of chemical reactions that occur in a single phase (gaseous, liquid, or solid), one of two broad classes of reactions—homogeneous and heterogeneous—based on the physical state of the substances present. heterogeneous reaction,  any of a class of chemical reactions in which the reactants are components of two or more phases (solid and gas, solid and liquid, two immiscible liquids) or in which one or more reactants undergo chemical change at an interface, e.g., on the surface of a solid catalyst

The speed of homogeneous chemical reactions and methods of its measuring.

"Catalysts is classified as homogeneous chemical reaction. A homogeneous catalyst is one that is present in the same phase as the reactants--for example, gases--while a heterogeneous catalyst is present in a different phase. For example, the chlorofluorocarbons (CFCs) that catalyze the destruction of ozone do so as homogeneous catalysts because they are gases. In the Antarctic, solid ice microcrystals function as heterogeneous catalysts, a phenomenon not prevalent in the Arctic.

6)Theory of active collisions. When a catalyst is involved in the collision between the reactant molecules, less energy is required for the chemical change to take place, and hence more collisions have sufficient energy for reaction to occur. The reaction rate therefore increases. Collision theory is closely related to chemical kinetics.

The rate constant for a bimolecular gas phase reaction, as predicted by collision theory is:

k(T)=Zp exp (-Ea/RT)

Arrhenius’ equation. Given the small temperature range kinetic studies occur in, it is reasonable to approximate the activation energy as being independent of the temperature. Similarly, under a wide range of practical conditions, the weak temperature dependence of the pre-exponential factor is negligible compared to the temperature dependence of the exp (-Ea/RT). factor; except in the case of "barrierless" diffusion-limited reactions, in which case the pre-exponential factor is dominant and is directly observable.

Arrhenius' concept of activation energy.

Arrhenius argued that for reactants to transform into products, they must first acquire a minimum amount of energy, called the activation energy Ea. At an absolute temperature T, the fraction of molecules that have a kinetic energy greater than Ea can be calculated from statistical mechanics. The concept of activation energy explains the exponential nature of the relationship, and in one way or another, it is present in all kinetic theories.

Vant-Hoff’s rule. A statement in physical chemistry: the effect of a change in temperature on a system in equilibrium is to shift the equilibrium in the direction that acts to nullify the temperature change <according to van't Hoff's law,an increase in temperature will cause an increase in the rate of an endothermic reaction>.

Temperature coefficient of the reaction speed for enzymatic processes. The  temperature coefficient of the reaction speed for enzymatic processes  is a measure of the rate of change of a biological or chemical system as a consequence of increasing the temperature by 10 °C. There are many examples where the Q10 is used, one being the calculation of the nerve conduction velocity and another being calculating the contraction velocity of muscle fibres. It can also be applied to chemical reactions and many other systems.

7) Osmose and osmotic pressure of solutions. Osmosis is the spontaneous net movement of solvent molecules through a partially permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides. It may also be used to describe a physical process in which any solvent moves across a semipermeable membrane (permeable to the solvent, but not the solute) separating two solutions of different concentrations. Osmotic pressure of solution is the pressure which needs to be applied to a solution to prevent the inward flow of water across asemipermeable membrane. It is also defined as the minimum pressure needed to nullify osmosis.

The phenomenon of osmotic pressure arises from the tendency of a pure solvent to move through a semi-permeable membrane and into a solution containing a solute to which the membrane is impermeable. This process is of vital importance in biology as the cell's membrane is selective toward many of the solutes found in living organisms.

Vant-Hoff’s law. The van 't Hoff factor  (named after J. H. van 't Hoff) is a measure of the effect of a solute upon colligative properties such as osmotic pressure, relative lowering in vapor pressure, elevation of boiling point and freezing point depression. The van 't Hoff factor is the ratio between the actual concentration of particles produced when the substance is dissolved, and the concentration of a substance as calculated from its mass. For most non-electrolytes dissolved in water, the van' t Hoff factor is essentially 1. For most ionic compounds dissolved in water, the van 't Hoff factor is equal to the number of discrete ions in a formula unit of the substance. This is true for ideal solutions only, as occasionally ion pairing occurs in solution. At a given instant a small percentage of the ions are paired and count as a single particle.

The pressure of saturated vapor of solvent above the solution. To make a solution, you need a solvent and a solute. Usually (but not always), liquid water is the solvent and some solid substance (sugar, for example) is the solute.

Notice the word "nonvolatile" in the title. The volatility of a substance refers to the readiness with which it vaporizes. Generally speaking, substances with a boiling point below 100 °C are considered volatile and all others are called nonvolatile. Ethyl alcohol and pentane are examples of volatile substances; sugar and sodium chloride are considered nonvolatile.

The presence of a solute leads to a colligative property called the "lowering of the vapor pressure of the solution" when compared to the vapor pressure of the pure solvent. This is not a nice, tidy name like osmosis, but then again, life itself is not always nice and tidy either. There is enough of a difference between the types (volatile and nonvolatile) of solutes to merit treating them separately.

Raoult's first law. Raoult's first law is a phenomenological law which assumes ideal behavior based on a simple picture just as the ideal gas law does. The ideal gas law is very useful as a limiting law. The validity of this law requests the microscopic assumption regarding intermolecular forces between unlike molecules to be equal to those between similar molecules: the conditions of an ideal solution. Now I'm going to explain how the solutes affect the freezing and boiling point of a solvent. Solutes increase the boiling point and solutes decrease the freezing point. solutes changes the boiling point of the solvent. when the solute is added in a solvent the boiling point of the solution increases. One example is, if salt is added to the water then the boiling point of water will increase to 100 degree Celsius. This happens because the boiling point is the temperature where the vapor pressure of the solvent becomes equal to the external atmospheric pressure. When solute is added in the solvent then solvent molecules take more time and temperature to make vapor pressure and causes the boiling point of the solvent increases.

Boiling and freezing temperatures of solvents. Now I'm going to explain how the solutes affect the freezing and boiling point of a solvent. Solutes increase the boiling point and solutes decrease the freezing point. solutes changes the boiling point of the solvent. when the solute is added in a solvent the boiling point of the solution increases. One example is, if salt is added to the water then the boiling point of water will increase to 100 degree Celsius. This happens because the boiling point is the temperature where the vapor pressure of the solvent becomes equal to the external atmospheric pressure. When solute is added in the solvent then solvent molecules take more time and temperature to make vapor pressure and causes the boiling point of the solvent increases.

Raoul’s second law. There are several ways of stating Raoult's Law, and you tend to use slightly different versions depending on the situation you are talking about. You can use the simplified definition in the box below in the case of a single volatile liquid (the solvent) and a non-volatile solute.

Cryoscopy -the determination of the lowered freezing points produced in liquid by dissolved substances in order to determine molecular weights of solutes and various properties of solutions.

Ebullioscopy. The boiling point of a liquid is the temperature at which its vapour pressure becomes equal to the external atmospheric pressure. The phenomenon that the boiling point of a solvent will be higher when another compound is added is known as Boiling point elevation, ie., the boiling point of a pure solvent will always less than its solution. 

8) Colligative properties of electrolyte solutions. Because vapor pressure is a colligative property, the vapor pressure of solutions is directly proportional the amount of solute present in a solution.

When a solute is present in a solvent, the vapor pressure is lowered because less solvent molecules are present at the top of the solution. These spots are occupied by solute molecules and effectively make it harder for solvent to leave the solution.

Isotonic coefficient- the amount of salts in the blood plasma, or the amount that should be added to distilled water to prepare an isotonic solution.

The theory of weak electrolyte solutions. Weak electrolytes are not completely ionized when dissolved in a polar medium like water. There exists equilibrium between ions and unionized molecules.

                                        AB ⇌  A+ + B-

(ii)  Concept of chemical equilibrium and law of mass action can be applied to ionic equilibrium also.

                                        AB  ⇌   A+ + B-

The theory of strong electrolyte solutions. The solution for the ion flux through a membrane channel that incorporates the electrolyte nature of the aqueous solution is a difficult theoretical problem that, until now, has not been properly formulated. The difficulty arises from the complicated electrostatic problem presented by a high dielectric aqueous channel piercing a low dielectric lipid membrane. 

9)The ion product of water. Water molecules can function as both acids and bases. One water molecule (acting as a base) can accept a hydrogen ion from a second one (acting as an acid). This will be happening anywhere there is even a trace of water - it doesn't have to be pure.

Hydrogen ion exponent pH. The pH of a solution describes its acidity and is the negative logarithm (log) of its hydrogen ion concentration. The term pH is used because the hydrogen ion concentration in solutions of weak acids and in many other fluids is frequently much less than 1. Therefore, when the concentration is expressed exponentially, it contains a negative exponent. Many people find numbers with negative exponents to be confusing, and they answer with some hesitation such questions.

Calculation of solution pH of weak and strong acids and bases. In this reaction a buret is used to administer one solution to another. The solution administered from the buret is called the titrant. The solution that the titrant is added to is called the analyte. In a titration of a Weak Acid with a Strong Base the titrant is a strong base and the analyte is a weak acid. In order to fully understand this type of titration the reaction, titration curve, and type of titration problems will be introduced.

10) The structure of complex compounds: inner sphere, outer sphere, central atom, ligands, coodination number, dentation of ligands.

Inner sphere or bonded electron transfer is a redox chemical reaction that proceeds via a covalent linkage—a strong electronic interaction—between the oxidant and the reductant reactants. In Inner Sphere (IS) electron transfer (ET), a ligand bridges the two metal redox centers during the electron transfer event. Inner sphere reactions are inhibited by large ligands, which prevent the formation of the crucial bridged intermediate. Thus, IS ET is rare in biological systems, where redox sites are often shielded by bulky proteins. Inner sphere ET is usually used to describe reactions involving transition metal complexes and most of this article is written from this perspective. However, redox centers can consist of organic groups rather than metal centers.

The bridging ligand could be virtually any entity that can convey electrons. Typically, such a ligand has more than one lone electron pair, such that it can serve as an electron donor to both the reductant and the oxidant. Common bridging ligands include the halides and the pseudohalides such as hydroxide and thiocyanate. More complex bridging ligands are also well known including oxalatemalonate, and pyrazine. Prior to ET, the bridged complex must form, and such processes are often highly reversible. Electron transfer occurs through the bridge once it is established. In some cases, the stable bridged structure may exist in the ground state; in other cases, the bridged structure may be a transiently-formed intermediate, or else as a transition state during the reaction.

Classification and nomenclature of complex compounds. Stable inorganic or ionic compounds can be classified as simple compounds and complex compounds. Simple compounds are those which are formed by two or more elements and can be bifurcated as positive and negative ions in the dissolved state or in the solution phase. The complex compounds are further divided into double salts and complex compounds or co ordination compounds. These are addition compounds formed by the combination of two or more stable compounds in stoichiometric proportions. Carnallite is a double salt formed when KCl and MgCl2 combine with 6molecules of water.(KCl.MgCl2.6H2O). Coordination complexes have their own classes of isomers, different magnetic properties and colors, and various applications (photography, cancer treatment, etc), so it makes sense that they would have a naming system as well.