Inorganic Chemistry: General Chemistry PDF

**INORGANIC CHEMISTRY:GENERAL CHEMISTRY** **CHEMISTRY** - The **"central science"** - It is the study of matter including their -chemical and physical properties \- chemical and physical changes it undergoes \- energy changes that accompany those processes **CHEMISTRY: THE CEN...

**INORGANIC CHEMISTRY:GENERAL CHEMISTRY** **CHEMISTRY** - The **"central science"** - It is the study of matter including their -chemical and physical properties \- chemical and physical changes it undergoes \- energy changes that accompany those processes **CHEMISTRY: THE CENTRAL SCIENCE** **DIVISIONS OF CHEMISTRY** General Chemistry Analytical Chemistry Inorganic Chemistry Biochemistry Physical Chemistry Nuclear Chemistry Organic Chemistry Geological Chemistry **MATTER AND ATOMS** A. **MATTER** - Anything that occupies space and has mass - **Mass** (proportion of elements)**-**measure of quantity of matter - **Weight-** gravitational force of attraction exerted by the earth on a body **Note: Mass and weight are interchangeable** which means it can be put or used in place of each other and no one would know the difference. B. **PURE SUBSTANCES -- (**made up of one type of particle and have fixed structure with definite properties) - **ELEMENT** - A pure substance that can **no longer be chemically decomposed** - Simplest form of matter - 1 kind of material or atom - **COMPOUND** - Substance composed of two or more elements united chemically in definite proportion. **Note:** To create a compound, we need two elements. Compound= E+E **Example:** Elements**: Na+Cl=NaCl or table salt (a compound)** - **LAW OF DEFINITE PROPORTIONS** (*[Joseph Proust]*) - a pure compound always consists of the same elements combined in the same proportion by mass C. **MIXTURE** - Composed of two or more substances that are not chemically combined - prepared from two or more pure substances NOT in fixed proportions and can be separated by physical means **[Classification of mixture based on Nature of Particles]** 1. **HOMOGENOUS** - mixture with only **ONE PHASE** - Consists of **uniform properties** throughout given samples - **Example**: NaCl dissolved in water **Note:** "**genous**"= origin and "**homo**"= same or 1 - We can make a homogenous mixture without 2 distinct components - **Example:** A solution wherein we add a solvent (often H~2~O) to a solute (NaCl- table salt) - **[Complete Dissolution-]** when there's no distinct layers appeared. 2. **HETEROGENOUS** - mixture with **MORE THAN ONE PHASES** - Consists of physically distinct parts - **Example**: Sand and water mixture - **Two distinct components can be seen** **[Classification of mixture based on Particle size]** 1. **Solution** - uniform mixture, composed of solute and solvent **Remember:** - The term **"dissolved/ dissociates "=** solution - **Particle size** affects the solubility. The **finer** the particle size, the higher the possibility of ***dissolution**.* 2. **Suspension**- aka Coarse (makapal) mixture \"finely divided solid materials distributed in a liquid\" 3. **Colloids** -particles of solute that are not broken down to the size of the molecules but are small enough to remain suspended and evenly dispersed throughout the medium **[Properties of Colloids]** - Tyndall effect- light scattering effect - Brownian motion- random motion by small particles suspended in the fluid - Adsorption - Charged **[SEPARATION OF MIXTURE]** - **Decantation** - Difference in specific gravity (depends on the gravity) - **Example**: Oil+Water - **Distillation** -the process of separating the components of a liquid mixture through selective evaporation and followed by condensation - **Evaporization** - escape of molecules from the liquid state to the gaseous state/vapor state - Conversion from liquid to gas= steam. We increase hot temperature to do this. - **Condensation**- gasliquid. We decrease temperature to cold. - **Magnetic separation** -- metals. Solute separates from solvents using a magnet. - **Filtration** -use of filter paper - **Sorting** - mechanical separation. We can sort materials manually. - The process of separating and arranging substances based on their physical or chemical properties. - **Centrifugation** - to increase settling of precipitate. - **Precipitate-** an insoluble solid that emerges from a liquid solution which settles at the bottom of the container. - **Fractional crystallization** - lowering the temperature so that the more insoluble component crystallized first; based on the difference in solubility - **Chromatography** - Difference in solvent affinity. A method by which a mixture is separated by distributing its components between two phases. - **Stationary**- not moving/ fixed in place (solute) - **Mobile**- moving/ carries components of the mixture through the medium (solvent) **[STATES OF MATTER]** **[INTERCONVERSERSION OF MATTER]** - **SoLi=Melting/fusion** - **SoGa= Sublimation** - **LiSo=Freezing** - **LiGa=Evaporation/Vapor(steam)** - **GaLi= Condensation (increase in temperature)** - **GaSo= Deposition\ ** **Example: Water** - Ice-solid - Liquid water- liquid - Steam/vapor- gas **Some points to remember:** - **IFA**= INTERMOLECULAR FORCES OF ATTRACTION ( IMF, IMFA) - **H~2~O- H~2~O= Hydrogen bond.** One of the weakest bond. But, it can be strong if there's an increase of IFA in the molecules. - **Cohesion**- the attraction of molecules for other molecules of the same kind - **Water Cohesion-** water molecules have strong cohesive forces thanks to their ability to form hydrogen bonds with one another. - **Interconversion-** in between. Converting of one physical matter to another matter. - **Fusion**- The process by which a substance changes from a **solid-state to a liquid state.** **We add heat or increase in temperature.** **A.SOLID AND THE CRYSTALLINIE STATE** - Intermolecular attractive forces are strong enough not only to hold molecules close together but virtually to lock them in place. - rigid have fixed volume - particles are packed tightly together - incompressible, expand only slightly when heated **CRYSTALLINE SOLID** - **Crystalline solids** have ordered, repeating, three-dimensional patterns of atoms, ions, or molecules; have sharper melting point; are all anisotropic except for cubic crystalline. - **Example**: NaCl, Wood, Graphite. - **Amorphous solids** (without form) have no orderly 3-D structure; more-or less random distribution of particles: are isotropic - **Amorphous**- no shape/form. - "**Morph**"- shape of from - "**A**"- lack of/ there is no - **Example**: Glass, rubber, plastics **1.CRYSTALLINE SOLID** - **Isotropic** - exhibit similar properties in all directions - **Iso**= same - **Examples:** glass, plastics, and metals - **Anisotropic** - exhibit different properties in different directions - **Aniso=** not the same/ different particles - **Examples:** graphite (such as in pencils), wood, and carbon fiber.  - Direction=uniformity - **Polymorphism** - ability of solid crystals to **exist in more than one** crystalline form - **Poly=** many - ***Polymorphs can be:*** - **[enantiotropic]** (**reversible** transition in polymorphic forms) or - **[monotropic]** (polymorphic transition occurs only in **one direction)** **2. LIQUID CRYSTALLINE** - Also known as MESOPHASE - **Meso=** middle where phases exist - fourth state of matter - have characteristics intermediate to those of solids and liquids **[CHARACTERISTICS:]** - Are organic - Are elongated and rectilinear in shape - Are rigid - Possess strong dipoles and easily polarizable groups **[TYPES OF LIQUID CRYSTALS]** - **Smectic** *(soap or grease-like)* - molecules are mobile in two directions and can rotate about one axis - **Nematic** *(thread-like)*- molecules are mobile in three directions and can rotate about one axis - **Cholesteric** - special type of nematic liquid crystals **Liquid crystalline state may result either from:** - **Heating of solids (**thermotropic liquid crystals) - **By action of certain solvents on solids** (lyotropic liquid cystals) **B. LIQUID** \- the intermolecular forces (IMF) are strong enough to hold the molecules close together but not strong enough to keep the molecules from moving past one another **[Consequence:]** - Liquids flow and assume the shape of the container but with definite volume - Liquids are denser than gases - Diffusion with a liquids occurs slowly - Liquids are incompressible and do not expand to fill the container **[DEFINITION OF TERMS:]** - **Boiling point (BP)**- temperature at which the vapor pressure of a liquid is equal to the external pressure acting on its surface. - BP Of water- 100 degree Celsius, depends on the altitude - **Vapor pressure** -pressure exerted by the vapor of a liquid when the liquid and vapor states are in dynamic equilibrium; escaping tendency of a liquid - **Freezing point-** temperature at which the solid and liquid are in equilibrium at l atm pressure - FP Of water- 0 ^o^C **[GENERALIZATIONS]** - The higher the vapor pressure of a liquid, the lower the boiling point - The stronger the IMF, the higher a liquid's BP **NOTE:** - Boiling point and Freezing point both applies temperature. - Increase vapor pressure= decrease of boiling point - Stronger IMF= increase of boiling point - Liquid and gas= equilibrium - Solid and liquid= equilibrium - **C.GAS** - Molecules are far apart, free to move inside the container **[CHARACTERISTICS:]** - no definite shape, assumes the volume of the container - highly compressible - flows readily - expands spontaneously **[TERMS]** - **Pressure**-a force that tends to move something in a given direction - Sl unit:N/m² = 1 Pa - l atm = 760 torr = 760 mmHg = 101.325kPa - **Temperature** - SI unit = K - K= °C+ 273.15 - **Standard atmospheric pressure** -typical pressure at sea level **[TYPES OF BONDS]** - **Intramolecular bonds -** bond within a molecule - lonic bonds - Covalent bonds - **Intermolecular bond-** bonds between molecules - Van der Waals Forces - lon dipole and ion induced dipole forces - Hydrogen bonds A. **IONIC BOND** - attraction for an anion and a cation after an electron is transferred from the metal to the non-metal - involves complete transfer of electron - cations and anions are held by electrostatic attraction **PROPERTIES OF IONIC BOND/IONIC COMPOUNDS** - ions forma geometric pattern (3-D) - ionic formula gives simplest ratio to form a neutral crystal (NaCi, KCI) good conductors of electricity when in solution high melting point - Ex. Na (l valence electron) → donates one electron - CI (7 valence electrons) → lacks 1 electron, which it accepts from Na B. **COVALENT BOND** - formed by sharing a pair of electrons - bond between nonmetals or between metalloids - leads to formation of molecules - Ex. Ha. Ch, HF **TYPES OF COVALENT BOND** - **Single bond -** shares 1 pair of e - ex. CHCI, H-Br - **Multiple bond** - shares 2 or more pairs of e - ex. O=O - **Bonding electron** - electron that are shared between atoms - **Non-bonding electron -** electron that are only in one atom and is not shared +-----------------------------------+-----------------------------------+ | IONIC BONDS | COVALENT BOND | +===================================+===================================+ | transfer of electrons | instead of transferring, | | | electrons are shared | | 2 ions (+, -) | | | | Examples: | | protons (positive charged), | | | electrons (negative charged), | H~2~= H-H | | neutron (neutral) | | | | Cl~2~= Cl-Cl | | Example: Na+Cl (metal+ Non metal) | | | | | | **Valence Electrons-** Outermost | | | shell. Sodium has 1 while | | | Chlorine has 7= 8 (octet which is | | | stable) | | +-----------------------------------+-----------------------------------+ **INTERMOLECULAR BOND: VAN DER WAAL'S FORCES** **Van der Waal\'s forces** +-----------------------+-----------------------+-----------------------+ | **Dipole-dipole or | **Dipole-induced | **Induced dipole** | | Keesom forces** | dipole or Debye | | | | forces** | | +=======================+=======================+=======================+ | orientation forces | induction forces | induced dipole or | | | | London forces | | partially positive | Some polar molecules | dispersion forces | | portion of one | induce some | | | molecule is attracted | interaction with | is the weakest | | to the partially | nonpolar molecules.  | intermolecular force, | | negative portion of | | it is temporary and | | another molecule | Example: interaction | it occurs in all | | | between water (polar) | molecules (polar and | | **Example**: Hydrogen | and xenon (nonpolar). | non-polar). | | chloride (HCl), | | | | hydrogen fluoride | | | | (HF), and water | | | +-----------------------+-----------------------+-----------------------+ **INTERMOLECULAR BOND: ION DIPOLE AND ION-INDUCED DIPOLE** - **ion-dipole** (accounts for solubility of ionic crystalline substances in water) - **ion-induced dipole forces** (accounts for solubility of iodine in potassium iodide) **INTERMOLECULAR BOND: HYDROGEN BOND** - Interaction between a molecule containing a hydrogen atom and a strongly electronegative atom such as F, O, or N **PROPERTIES OF MATTER** - **Extrinsic or extensive properties** (depends on the quantity of the material) - Qualities that are not characteristic of the substance itself - Those that depend on the amount of energy or **quantity** of materials present - **Example**: weight, volume, pressure, heat content (measurable) - **Intrinsic or intensive properties** (Does not depend on the quantity) - Qualities that are characteristic of any sample of a substance regardless of the shape or size of the sample - Those that are depend on the **quality** or kind of material that: - Cannot be measured (taste, color, odor) - Measurable (Melting point, Boiling point, Density, Specific gravity) **CHANGES IN MATTER** - **Physical change-** No new substance is formed - **Interconversion phase** - **Ex:** Solid- Ice Liquid- Liquid water Gas- steam/vapor - **Chemical change-** Changed in both intrinsic and extrinsic properties. New substance is formed - **Example:** rust, burning - **Nuclear change-** Change in structure, properties, composition of the nucleus of an atom resulting in the transmutation of the element into another element. - **Nuclear fission** - splitting of a heavy atom - **Nuclear fusion -** union of 2 light atoms to form bigger molecule. **EVIDENCE OF CHEMICAL CHANGE** - Evolution of gas (vapor, carbon dioxide emission) - Formation of a precipitate (insoluble substances compound A + compound B= precipitate - Emission of light - Generation of electricity - Production of mechanical energy - Absorption or liberation of heat **PROCESS INVOLVED IN CHEMICAL CHANGE** A. **Oxidation** - **LEORA** ( **L**oss of **E**lectrons **O**xidation **R**educing **A**gent) - **Oxidation** (+) Oxygen - **Dehydrogenation** (-) Hydrogen(addition of Oxygen while reducing hydrogen) B. **Reduction** - **GEROA** (**G**ain of **E**lectrons **R**educing **O**xidizing **A**gent) - **Hydrogenation** (+) Hydrogen (less of Oxygen while gaining Hydrogen) - **Reduction** (-) Oxygen **REDOX** -- balance of Oxygen and Hydrogen C. **Neutralization-** Salt formation Reactants: Acid+Base= Salt Metal+Non Metal (Na+Cl=NaClsalt) HCl+ NaOH NaCl+ HOH(water) D. **Hydrolysis** - breakdown of molecule/complex compound in the presence of water (by addition of water) E. **Saponification-** soap formation - **NaOH** detergent (hard soap) - **KOH** bath soap (soft soap) F. **Fermentation-** Alcohol+ CO~2~ (Formation of Alcohol and Carbon Dioxide) - Why do we use grapes when making mine? Because it contains **sugar** (complex compound) and we add **water**= Hydrolysis - You can also add catalyst like yeast, heat, vinegar, and enzymes. **NOTE**: - **Ethanol**= CH~3~-CH~2~-OH - **Alcohol**: R(Alkyl)-DH(Hydroxyl)+CO~2~(released when you opened the bottle) - **How can you know that you are already tipsy (process)?** - **Alcohol** (when this oxidize) **Aldehyde** (Nausea/Vomit) **carboxylic acid** (in the form of urine) - **Carboxylic Acid is water soluble.** **LAWS GOVERNING MATTER AND ENERGY** - **Law of Mass Action-** The rate of the reaction is proportional to the product of the concentrate of the reactants to the power of its coefficient in a balanced equation. - aA + bB cC + dD - **Law of Conservation of Energy-** Energy can neither be created nor destroyed, but it can be transformed from one form to another. - **Law of Conservation of Mass-** No change is observed in the total mass of the substances involved in chemical reaction. - **Law of Constant Composition** - Law of Definite Proportion - Proust\'s Law- States that \"in a pure compound, the elements are always present in the same proportion by mass\" - **Example:** H20 - **Law of Multiple Proportion-** Atoms of two or more elements may combine in the different ratio to produce more than one compound. A. **Combination Reaction** (Direct Union or Synthesis or Composition) - Two or more substances ( either elements or compounds) react to form one product - From simple substances to complex substances - A+B → AB **TYPES OF COMBINATION REACTION:** - Metal+ Non Metal **Binary Compound** **Ex:** 2K+Cl~2~=2KCl (Potassium Chloride) - Non Metal+ Oxygen **Non Metal Oxide** **Ex:** S+O~2~ SO~2~ (Sulfur dioxide) - Metal Oxide+ Water **Metal hydroxide** **Ex:** CaO+ H~2~O Ca(OH)~2~ (Calcium Hydroxide) - Non Metal Oxide+ Water **Oxyacid** **Ex:** SO~2~+ H~2~O H~2~SO~3~ (Sulfurous Acid) - Metal Oxide+ Non Metal Oxide **Salt** **Hydroxide**- inorganic while **Hydroxyl**- inorganic B. **DECOMPOSITION REACTION** - One compound decomposes to form 2 or more new substances - From complex substances to simple substances - Products form: elements or compounds - Often, heat is necessary for the reaction to occur - **Example**: 2NaHCO3 2CO2 + H20 Na20 **TYPES OF DECOMPOSITION REACTION:** - **Hydrate**, when heated , decompose to yield water and anhydrous salt. - **Chlorates**, when heated, decompose to form chlorides and oxygen gas - Few metal oxides decompose when heated to form free metal and Oxygen gas - **Ex: 2 HgO→ 2 Hg +O,** - Water can be broken down into hydrogen and oxygen by direct electric current. - Most Carbonates, when heated decompose to form oxides and carbon dioxide - **Ex: CaCo,→ CaO + CO,** - GROUP 1A carbonates do not decompose readily - Most bicarbonates , when heated, decompose to form oxides, water and Carbon dioxide - Group 1A bicarbonates form it\'s corresponding carbonate, water and carbon dioxide when heated. - **Ex: 2NaHCO, → NaCO, + HaO+ CO,** C. **REPLACEMENT/DISPLACEMENT REACTION** - Metal replaces another metal ion from a solution - Free metal must be more active than the metal that is in the solution Metals arranged in series - \"Activity series\" or \"Electromotive series\" Used to predict the products of replacement reaction - Any free metal located higher on the list will displace another metal that is lower from solution - Any metal above H on the activity series will displace hydrogen gas from an acid **SINGLE REPLACEMENT/ DISPLACEMENT REACTION** - For **NOMETALS-** their activity is related to their ability to gain electron and form anion **More gaining of electrons**= high formation of anion (negative charged ion) Ex: chlorine chloride Flourine flouride - For **METALS-** their activity is related to their tendency to lose electron and form cation **Lose of electron**= formation of cation (positive charged ion) **SIMPLE REPLACEMENT-** Atoms of an element replace an atom ofa single element in a compound - 2Na +2 H,O→ 2 NaOH + H - Mg + Zn(NO,), → Mg (NO3), + Zn **METATHESIS/DOUBLE DISPLACEMENT REACTION** - Two compounds react to form new compounds - General reaction: AB + CD → AD + BC - Many reactions involved formation of an insoluble compound - SOLUBILITY RULES!!! - Some involved formation of an nonionized substances **SOLUBILITY RULES** - Almost group lA and ammonium **salts are water soluble NH~4~-** Clamonium - All nitrates (NO~3~), acetates and chlorates (ClO~3~) are soluble - All common chlorides are soluble, **except** AgCI, Hg~2~,Cl~2~, and PbCl~2~ ( silver, mercury, lead are heavy metals) - PbCI~2~, is quite soluble in hot water **SOLUBILITY RULES** - All sulfates are soluble **except** CasO, , SrSO, , BasO, PbSO, (**Calcium, Strontium, Barium, Lead)** - All sulfides are insoluble **except** those of alkaline earth metals (2A in the periodic table **Be** down to **Ra**) and alkali metals ( From 1A **except** Hydrogen. **Li** down to **Fr**) - All oxides and hydroxides are insoluble except alkali metal compound - Oxides and hydroxides of Ca, Sr, Ba, are slightly soluble (when we add heat) - All phosphates and carbonates are insoluble except those of alkali metals **NEUTRALIZATION REACTION** - Actually metathesis reactions that involved nonionized substances (water) - Acid or acid oxides react with a base basic oxides with subsequent formation of salts - Water NOT formed when a metal oxide combines with a nonmetal oxide - Acid + Base \> water + salt - **Ex: HCl+ NaOH NaCl + HOH= Water + Salt** - Metal oxide + Acid →water + salt - **Ex: CaO + HCl CaCl** - Nonmetal oxide+ Base →water + salt - Metal oxide + acid oxide \> salt - Ammonia + acid → Ammonium salt - **Ex: NH~3~+ HCl NH~4~+Cl** **REDOX REACTION** - **LEORA**( Lose of electrons\\Oxidation \\Reducing agent) - **GEROA**( Gain of electrons\\Reduction\\Oxidizing agents) **Some common examples** - **OA:** PERMANGANATE, BROMATE,IODATE, CHLORINE, BROMINE, DICHROMTE - **RA**: Sn, Zn, Mg ,sodium borohydride **ATOM, MOLECULE & ION** +-----------------------------------+-----------------------------------+ | **ATOM** | Come from the Greek word | | | **atomos**, meaning uncut or | | | indivisible. | | | | | | Smallest particle of an element | +===================================+===================================+ | **MOLECULE** | Smallest unit of a compound | +-----------------------------------+-----------------------------------+ | **ION** | positive or negative charged atom | | | (+) ion= cation & (-) ion= anion | +-----------------------------------+-----------------------------------+ **SUBATOMIC PARTICLES** +-----------------------------------+-----------------------------------+ | **PROTON** | 1.0073 amu | | | | | | Eugen Goldstein | +===================================+===================================+ | **NEUTRON** | 1.0087 amu | | | | | | James Chadwick | +-----------------------------------+-----------------------------------+ | **ELECTRON** | 1/1840 amu | +-----------------------------------+-----------------------------------+ | **HYPERON** | Combination of 3 quarks: particle | | | with mass \> than that of | | | nucleon. | +-----------------------------------+-----------------------------------+ | **MESON** | particle with mass \> than that | | | of lepton but \< than that of a | | | nucleon | +-----------------------------------+-----------------------------------+ | **LEPTON** | particle with mass \< than or = | | | to that of an electron | +-----------------------------------+-----------------------------------+ | **POSITRONS** | (+) charged with a mass of: | | | 1\\1840 | +-----------------------------------+-----------------------------------+ | **NEGATRONS** | (-) charged with a mass of: | | | 1\\1840 | | | | | | known as electron | +-----------------------------------+-----------------------------------+ | **NEUTRINO** | Charged and mass is 0. | +-----------------------------------+-----------------------------------+ **ATOMIC SYMBOLS** - **Atomic Number (z) is the number of protons; dictates the identity of atom** - **Mass Number (a) = no. of protons + no. of neutron** **DEFINITION OF TERMS:** - **Isotopes-** atoms of the same elements that have the same atomic number (\# of p+) but different mass. **Ex**: Calcium - **Isobars-** atoms of different elements having the same mass numbers. **Ex:** Potassium-40, Argon-40 - **Isotones**-atoms of different elements having **Ex:** Sulphur-36, Chlorine-37, Argon-38, Potassium-39, and Calcium-4 **DISCOVERY OF ATOMS & ATOMIC MODELS** - **Continuous theory-** proposed by early Greek philosophers which states that matter is infinitely divisible. - **Atomistic Theory-** Proposed by Leucippus and Democritus. - Matter can be subdivided ultimately yielding **atomos** (pounded up materials in his mortar and pestle until he had reduced them to smaller particles). - Matter is made up of indivisible particles - **Dalton\'s Atomic Theory- \"billiard ball model\"** - All matter is made up of atoms. - Atoms of an element are identical. - Each element has different atoms. - Atoms of different elements combine in constant ratios to form compounds. - Atoms are rearranged in reactions. **Daltons proposed his atomic theory on the basis of** three generalizations: - **Law of Conservation of mass-** By Antoine Laurent Lavoisier - There is no detectable change in mass during the course of a chemical reaction. - Mass of reactants = Mass of products - **Law of Definite Proportions or Law of Constant Composition** - **Law of Multiple Proportion** - **George Johnstone Stoney** proposed that units of electrical charge are associated with atoms. - **Julius Plucker** discovered cathode rays ( negatively charged rays causing walls opposite them to glow) - **Robert Millikan** performed the oil drop experiment to determine the charge of an electron. - **Gold film experiment** - Most particles passed through. So atoms are mostly empty. - Some positive a-particles are deflected or bounded back. - Thus a \"nucleus\" is positive and hold most of an atom\'s mass. - **Natural Radioactivity by Henri Becquerel** - The spontaneous emission of radioactive rays by an unstable atomic nucleus, which in the process is transformed into a different nucleus. +-----------------------+-----------------------+-----------------------+ | ALPHA | BETA | GAMMA | +=======================+=======================+=======================+ | identical with Helium | Has same properties | similar to X-ray | | nuclei but less two | as electrons | Radiated as photons | | electrons | | or quanta of energy | | | Speed 0.4 time speed | at a velocity of 3.0x | | Speed - 0.05 times | of light Charge: -1 | 10\*12 m\\s Charge :0 | | speed of light | | Electromagnetic in | | | **More penetrating** | nature unlike the | | Charge: +2 | than alpha radiation. | alpha and beta | | | | particles. | | **Low penetrating | | | | power:** stopped by | | **Most penetrating | | sheet of paper. | | among the three**( up | | | | to 25 cm tissue) | | | | Discovered by **Paul | | | | Villard** and | | | | **Pierre Curie** | +-----------------------+-----------------------+-----------------------+ - **Planetary Model by Neil Bohr** - Proposed the structure is Iike **a mini solar system** where electron only orbit around the nucleus in particular energy levels or shells. - **Ground State:** lowest allowed energy state for an electron. - **Excited State:** electrons move to higher energy level when it gains quantum of energy. - **Heisenberg\'s Uncertainty Principle**- It is impossible to determine, simultaneously, the exact position and the exact momentum of an electron. - **Quantum Mechanical Model by E. Schroedinger** - derived many mathematical equations to measure the probability of finding an electron in a volume of space called Orbitals: position of electron is defined in terms of probability density. - **Electron cloud -** represernts the greatest probability in a region where there is greatest electron density. - **Pauli Exclusion Principle** - No two electron in an atom may have exactly the same set of 4 quantum numbers. - 2 electrons may have the first 3 quantum numbers alike but they would definitely have opposing spin - Only two electrons may occupy the same orbital and these electrons must have opposing spins. - **Hund\'s Rule** - When orbitals of identical energy( degenerate orbitals) are available, electrons initially occupy these orbitals singly. - Since electrons all carry the same electric charge, they try to get far apart as possible and they do this by seeking out first empty orbitals of similar energy in preference to pairing up ina half-filled orbitals. - **Aufbau Principle** - German for **\"building up\"** by Wolfgang Pauli - Electrons occupy the lowest energy sublevels that are available - 2 common variations in filing: Cr and Cu - ^24^Cr instead of 4~s~^2^3d^4-^ → 4~s~^1^3d^5^ - Added stability in 2 sets of half filled orbitals - From Hund\'s rule half filled set of d orbitals favors symmetrical distribution - ^29^Cu: Instead of 4~s~^2^3d^9^ 4~s~^1^3d^10^ - Added stability 1\\2 filled s and completely filled d.