The properties of visible light and other forms of electromagnetic radiation led to the electronic structure of atoms.
Albert Einstein used Plank’s theory to explain the photoelectric effect.
Max Planck proposed that energy is absorbed and emitted in discrete amounts or individual packets called QUANTA.
The concept of quantized electrons grew from the study of line spectra of atoms.
Louise de Broglie discovered the wave nature of matter which initiated the development of a new mathematical description of electron configuration.
Niels Bohr used the line spectra to explain specific energy levels within the atoms.
Heisenberg’s uncertainly principle explained the impossibility of simultaneously measuring the momentum and location of an electron. Erwin Schrodinger devised the quantum mechanical model of the atom which described electrons as waves that exist in quantized energy levels.
Chemical bonds are classified into three group: ionic bonds, which are the electrostatic forces between ions of opposite charges; covalent bonds, which result from the sharing of electrons by two atoms.
A polar covalent bond is formed when electrons are not shared equally between two atoms.
Electro negativity deference of bonded atoms determines the kind of bond formed between the atoms.
These bonds involved the valence electrons with the tendency of atoms to follow the octet rule.
The charges or oxidation numbers of the ions of representative elements are determined by their position in the periodic table.
Most transition metals have more than one common ionic or oxidation numbers. A polyatomic ion a group of atoms that behaves as an ion that has a change.
Binary ionic compounds are named by writing the name of the caution followed by the name of the anion. Binary compounds end in –ide. If caution have more than one ionic charge, a roman numeral is used in the name.
Ternary ionic compounds contain at least one polyatomic ion. The names of these compounds end in -ite or-ate.
Bases are compounds containing a metal ion and hydroxide ion(OH-). Bases are named by writing the name of the caution followed by hydroxide.
The physical properties of gases are given by four quantities: Pressure P Volume V Temperature T Amount of Gases n
The behavior of gases can be explained by the kinetic molecular theory.
The standard temperature and pressure (STP) is 0°C and 1 atm. Atmospheric pressure is the pressure exerted by the gases (air) around us which is 1 atm or 760 mm HG. Boyle’s law states that the pressure and volume of a gas are inversely proportional to its absolute temperature (constant n and T).
Charles law states that the volume of a gas is directly proportional to its absolute temperature (constant n and P). Avogadros law states that equal volumes of gases contain the same number of particles (constant T and P). Ideal gas equation PV=nRT is a combination of the gas laws.
Daltons law states that the pressure of a mixture of gases is the sum of the partial pressure of the component gases. Real gases behave like ideal gases in ordinary conditions except at high pressure and low temperature. Lighter gases diffuse and effuse faster than heavier gases do.
At room temperature, substances with weak intermolecular forces of attraction are gases; those with moderate intermolecular forces are liquids; and those with strong intermolecular forces are solids.
Intermolecular forces include ion-dipole forces, dipole-dipole forces, London dispersion forces and hydrogen bonds.
Physicals properties of liquids and solids are explained by the kinetic molecular theory. Liquids possess properties such as viscosity, surface tension, capillarity evaporation, boiling point, and critical temperature and pressure.
Heating curve is a plot of temperature versus heat for phase changes. The properties of solids are explained based on their nature and strength if intermolecular forces of attraction.
A phase diagram indicates the states or phases of a substance under specific temperatures and pressures.
Solutions are homogeneous mixtures of two or more substances in a single phase. A solutions is made of solute, the substance that dissolves, and solvent, the substance in which the solute is dissolved.
A substance that dissolves in another substance is soluble (miscible) and if it does not, it is insoluble (immiscible). Solutions are either gaseous, liquids, or solid solutions.
In preparing dilute solutions form concentrated solutions, the number of moles before dilutions is equal to the number of moles after dilutions.
Saturated solutions contains the maximum amount of solute it can dissolve at a given temperature. Unsaturated a solutions that contains less than the maximum.
Supersaturated a solution with more than the maximum. Solubility is the extent to which a solute dissolves in a given solvent.
Chemical kinetics is the study of rate and sequence of steps by which chemical reactions occur. The rate of a reaction is the measure of how reactants turn into products.
Collisions theory assumes that particles collide at the proper orientation and with sufficient energy in order to react.
Activation energy is the minimum energy required for a chemical reaction to occur and make the reactant form an activated complex or transition state.
The factors that affect the rate at which a chemical reaction proceed are nature of the reactants, concentration of the reactants, temperature at which reaction occurs.
A rate law for a reaction describes the relationship between the concentration of reactants and the reaction rate. Most chemical reactions proceed through a series of elementary steps. The series of steps called the reaction mechanism.
The slow reaction in a reaction mechanism called the rate- determining step.
Thermodynamics is the study of processes which involve heat transfer and the performance of work. Thermochemistry is the study of this heat exchange and work on chemical reactions. Energy + Energy = constant: law of conversation of energy.
3 types of system : Open Closed Isolated An open system allows the transfer of both energy and matter into and out the system through a boundary or wall. A closed system is only capable of transferring energy through boundary.
An isolated system is not capable of transferring both energy and matter into and out of the system through a boundary or wall. Heat is a transfer of energy between system and surrounding due to temperature difference.
Equilibrium is a state at which there is “balance of forces”. 3 types of equilibrium: Mechanical Thermal Chemical
Chemical equilibrium is achieved when the rate of the forward reaction is equal to the rate of the reverse reaction and the amount of components remains unchanged.
Reversible reactions is an incomplete reactions. The reaction is represented by using a double headed arrow (═). Law of mass reaction states that the compositions of a reaction mixture can vary according to the quantities of components that are present.
The operational definitions of acids and bases are based on experimental results from the laboratory which includes color change using dyes. Arrhenius acids is a neutral substance that ionizes when it dissolves in water to give the H+ or hydrogen.
Arrhenius base is a neutral substance that gives the OH-, or hydroxide ion when dissolves in water.
Lewis defines an acids as species that can accept a pair of electrons while a base is a species that can donate a pair of electrons. The degree of ionization, not the concentration, classifies an acid or a base as weak or strong.
Compounds with more than one proton to give are called polyprotic acids.
Electrochemistry is the branch of chemistry that deals with electricity and its relation to chemical reactions. A chemical reactions were loss of electron(s) is involved id called oxidation while reaction where electron(s) is gained is called reduction.
Redox reaction can be balanced by using the oxidation number method or the ion electron method. Electrochemical cell, voltaic cell, or galvanic cell converts chemical energy from spontaneous reaction to produce electricity.
Electrochemical cell is composed of the electrodes and charge carriers.
Anode is the electrode where oxidation occurs. Cathode is where reduction occurs or where electrons are accepted. There 3 types of electrodes: Inert Metallic Membrane
Many elements have at least one radioactivity isotope or radioisotope. Elements with atomic numbers 83 or greater are all radioactivity. Radioactivity decay of naturally occurring radioisotope produces alpha particles, beta particles, and gamma radiations.
The half-life of a radioisotope is the time it takes for one-half of a sample of the isotope decay. In artificial radioactivity or artificial transmutation, the nucleus of an atom is bombarded with a particle or radiation and changed into different nuclei.
In balancing nuclear equation, the sum of the mass numbers and atomic numbers of reactants must be equal to the sum of the mass numbers and atomic numbers of the product. The mass defect in a nucleus is due to the strong forces of attraction that bind nucleons together.
Organic compounds are basically made up of carbon atoms bonded mostly to hydrogen, oxygen, nitrogen, and sulfur. Organic chemistry the study of the carbon-based compounds. Hydrocarbons are made up of carbons and hydrogen.
Alkanes also called saturated hydrocarbons, have an sp3 hybridization, four sigma bonds with no pi bonds that can be bound to H or C atoms. Alkenes are hydrocarbon containing a carbon-carbon double bond.
Alkynes are hydrocarbons containing a carbon-carbon triple bond.
Cycloalkanes are aliphatic cyclic (alicyclic) compounds which have general ring structure containing –CH- . A molecule can only be aromatic if it has the following properties: (1) the molecule is planar and (2) has a monocyclic system of conjugation with a total of (4n + 2) p electrons where n is an integer.