Atom, Elements and Compounds.pdf

Dr. Jose G. Tamayo Medical University Atom, Elements and Compounds UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Learning objective: Explain the structure of the atom in terms of the results of the scientific findings of different sc...

Dr. Jose G. Tamayo Medical University Atom, Elements and Compounds UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Learning objective: Explain the structure of the atom in terms of the results of the scientific findings of different scientists. COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Atomic Theory Democritus Aristotle Dalton COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Dalton’s Atomic Theory 1. Matter is made up of extremely small and indestructible particles called atoms. 2. All atoms of a given element are identical. 3. Atoms can enter into combination with other atoms in simple specific ratios 4. Chemical reactions only involve separation, combination or rearrangement of atoms. No atoms are created nor destroyed. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Joseph Lois Proust Theory Law of definite proportion: - two samples of a given compound are made up of the same elements in exactly the same mass proportions regardless of the sizes and sources of the sample. Law of multiple proportions - If two elements combine and form more than one compound, the mass of one element that combines with a fixed mass of the other element are in ratios of small whole numbers. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Joseph Lois Proust Theory Law of conservation of mass - Matter (and energy) can neither be created nor destroyed. COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Atoms - the buildings blocks which make up substances. - may be held together in a variety of ways resulting in the formation of compounds. - The smallest unit of an element that can enter into a chemical reaction. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY ATOMIC STRUCTURE Democritus – “Atomos” Dalton – “Billiard Ball Model” Thomson – “Raisin Bread Model” / electron Rutherford – “Gold Foil Expt” / proton in the nucleus James Chadwick – Neutron Bohr – “Planetary Model” Schrodinger – “Quantum Mechanic Model” / 3D model COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY ATOM Basic unit of Matter Gk. “atomos” – indivisible Sub-atomic particles: Found in the NUCLEUS …. Kaya they are collectively called ✓Proton – (+) charge NUCLEONS…. xD ✓Neutron- No charge GUYS TAKE NOTE that it ✓Electron- (-) charge is 1,836 times lighter than a proton; thus, the weight is negligible, okie? ☺ COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Atomic Symbol COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Things to remember: Atomic number = # of protons = # of electrons Mass number = # of protons + # of neutrons = atomic number (Z) + number of neutrons COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Definition of Terms Isotope – Same no. of protons (so same element), but diff. no. of neutrons Isotone- same number of Neutrons Isobar- same mass number COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Isotopes of Hydrogen COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY QUANTUM NUMBERS 1. Principal Quantum Number (n) - describes the MAIN ELECTRON SHELL and the SIZE of the e- cloud Value: 1,2,3,4…. 2. Angular / Azimuthal Quantum Number (l) - describes the SUBSHELL and the SHAPE of the e- cloud Value: 0 up to n-1 COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY QUANTUM NUMBERS 3. Magnetic Quantum Number (Ml) -describes the ORBITAL or ORIENTATION in space Values: -l , 0 , l 4. Spin (Ms or s) Values: +1/2 or -1/2 COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Rules Governing the Allowed Combinations of Quantum Numbers The three quantum numbers (n, l, and m) that describe an orbital are integers: 0, 1, 2, 3, and so on. The principal quantum number (n) cannot be zero. The allowed values of n are therefore 1, 2, 3, 4, and so on. The angular quantum number (l) can be any integer between 0 and n - 1. If n = 3, for example, l can be either 0, 1, or 2. The magnetic quantum number (m) can be any integer between -l and +l. If l = 2, m can be either -2, -1, 0, +1, or +2. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY n=3 n=4 l = 0, 1, 2 l= Ml = -2, -1, 0, 1, 2 Ml = COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Rules / Principles 1. Pauli’s Exclusion Principle - No 2 e- can have the same set of quantum numbers 2. Aufbau’s Principle - “Building up” Principle - Electrons are placed first on the subshell with lowest energy level 3. Hund’s Rule - Electrons are spread singly before pairing up COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Electron Configuration Make your own Mnemonics Give the Electron Configuration of the following: Beryllium (At. No. 4) Calcium (At. No. 20) COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY The Periodic Table of elements Lavoisier – 1st to set up the table (33 elem) Dobereiner – Triads - the iron triad comprises iron (Fe, cobalt (Co), and nickel (Ni) Newland – Law of Octaves - 8 elements are grouped before another set of 8 elements Meyer & Mendeleev – 1st Periodic Law; properties are periodic functions of atomic wt. Moseley – first modern Periodic Table NOTE: 118 elements, 18 groups/families, 7 periods or series COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Periodic Trends Atomic Radius  ½ the distance between 2 nuclei  Right to left increases  Top to bottom increases Electronegativity  Ability to attract electrons  Left to right increases  Going up increases Ionization energy or potential  Ability to remove an electron from a positively charged atom  Left to right increases  Going up increases Electron affinity  Property to accept an electron  Right to left increases  Top to bottom increases COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Periodic Trends COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY The Periodic Table separate ppt. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Element Pure chemical substance Contains only 1 type of atom Currently, there are 118 elements COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY LET’s DO THIS ☺ COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Properties of elements Electronegativity – ability of an element to attract electrons to itself Electron Affinity – energy gained by an atom when an electron is added to it Ionization Energy / Ionization Potential – amount of energy required to remove an electron from a neutral atom COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Elements –a fundamental or elementary substance that cannot be broken down by chemical means to simpler substances. - The building blocks of all substances. The elements are numbered in order of increasing complexity beginning with hydrogen, number 1. Of the first 92 elements, 88 are known to occur in nature. The other four – technetium (43), promethium (61), astatine (85), and francium (87) – either do not occur in nature or have only transitory existences during radioactive decay. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Elements that exists as Diatomic molecules – contain exactly 2 atoms 7 elements exist as diatomic molecules H2 - colorless gas N2 - colorless gas O2 - colorless gas F2 - pale yellow gas Cl2 - yellow-green gas Br2 - reddish-brown liquid I2 - Bluish-black solid COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY With the exception of number 94, plutonium, elements above 92 are not known to occur naturally, but have been synthesized in small quantities in the laboratories. The synthesis of element 110 was reported in 1994. *Substances can be decomposed into two or more simpler substances – examples: water, sugar, table salt. *an element cannot be decomposed into simpler substances by ordinary chemical changes. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY *Elements are distributed unequally in nature. - At normal room temperature, two of the elements, bromine and mercury are liquids. - 11 elements, H, N, O, F, Cl, He, Ne, Ar, Kr, Xe, & Rn are gases - All the other elements are solids COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY 10 elements make up about 99% of the mass of the earth’s crust, seawater, and atmosphere COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Names of the elements - Derived from Greek, Latin or German words that describe some property of the element. Example: a. iodine taken from the Greek word iodes, meaning violetlike, an iodine is violet in vapor state. b. Bismuth originates from the German words weisse masse, which means white mass. Miners called it wismat; later changed to bismat and to bismuth. - Some elements are name for the location of their discovery – e.g. germanium, discovered in 1886 by a German chemist. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Others are named in commemoration of famous scientists, such as einsteinium and curium, named for Albert Einstein and Marie Curie. *Symbols of the elements - Abbreviations used to describe elements are called symbols *14 elements have a single letter as their symbol and the rest have two letters. *Rules governing the use of symbols: 1. Symbols have either one or two letters 2. If one letter is used, only one letter is capitalized 3. If two letters are used, only the first is capitalized COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Activity: Read the symbols of the most common elements in the periodic table. Symbols of the elements derived from early names: Present Name Symbol Former Name Antimony Sb Stibium Copper Cu Cuprum Gold Au Aurum Iron Fe Ferrum Lead Pb Plumbum Mercury Hg Hydragyrum Potassium K Kalium COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Present Name Symbol Former Name Silver Ag Argentum Sodium Na Natrium Tin Sn Stannum Tungsten W Wolfram COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Elements are classified as metals, non-metals and metalloids. A. Metals are solids at room temperature (except for Hg). Characteristics: a. They have high luster b. Good conductors of heat and electricity c. Malleable (can be rolled or hammered into sheets) d. Ductile (can be drawn into wires) e. Have high melting point and high density Examples of metals: Al, Cr, Cu, Au, Fe, Pb, Mg, Hg, Ni, Pt, Ag, Sb, & Zn. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Other metals of importance include: Ca, Co, K, Na, U, & Ti. B. Nonmetals Are not lustrous Have relatively low melting point and densities Poor conductors of heat and electricity Examples: C, P, S, Se, I are solids; Br is a liquid Common nonmetals found uncombined in nature are carbon (graphite and diamond), N, O, S, and the noble gases He, Ar, Ne, Kr, Xe, and Rn) COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Nonmetals combine with one another to form molecular compounds such as (CO2) , methane (CH4), butane (C4H10), and sulfur dioxide (SO2). F the most reactive non-metal, combines readily with almost all other elements. C. Metalloids have properties that are intermediate between those of metals and nonmetals. Examples: B, Si, Ge, As, Sb, Po B, Si, Ge are raw materials for the semiconductor devices that make our modern electronics industry possible. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Matter Pure substances Mixtures of two (homogeneous compounds) or more substances Elements Compounds Solutions Heterogeneous (one phase) mixtures (2 or more phases) COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY A substance is a particular kind of matter with a definite, fixed composition – also known as pure substances Substances elements compounds H, O, Ca, S water, salt, sugar COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Homogeneous - uniform in appearance and has the same properties throughout. Heterogeneous – matter consisting of two or more physically distinct phases Phase – a homogeneous part of a system separated from other parts by physical bounderies. System –the body of matter under consideration. Mixture – a material containing two or more substances and can be either homogeneous or heterogeneous, variable in composition. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Compounds – a distinct substance that contains two or more elements chemically combined in definite proportion by mass. - Can be decomposed into simpler compounds and or elements. 2 types of compounds: 1. Molecular – consists of molecule which is the smallest uncharged individual unit of a compound formed by the union of two or more atoms. Ex. Water –a drop of water can be divided into smaller and smaller particles; consists of two hydrogen atoms bonded to and oxygen atom. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY 2. Ionic – contain ions which may be positively or negatively charged atom or group of atoms held together by attractive forces that exist between positively and negatively charged ions. *Cation – positively charged ion *Anion – negatively charged ion Example of ionic compound: sodium chloride (NaCl) Na+1 and Cl-1 Mg+2 PO4-3 = Mg3(PO4)2 Ca+2 CO3-2 CaCO3 COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Compounds Molecular Ionic Cations Anions (held together by attractive forces bet. + & -) Molecules composed of two or more elements (held together by covalent bonds) COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Properties used to identify substances Intensive/Intrinsic vs. Extensive/Extrinsic Physical Properties – observed or measured without changing the identity of matter Ex. MP,BP,Solubility,Ƿ, malleability, ductility Chemical Properties – describe the change or the reaction a substance undergoes Ex. Flammability, reactivity, inertness COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Properties of Matter: 1. Physical properties – inherent characteristics of a substance that can be determined without altering its composition. 2. Chemical properties – describe the ability of a substance to form new substances, either by reaction with other substances or by decomposition. COLLEGEOFPHARMACY  UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Physical properties of Chlorine, Water, Sugar, and Acetic Acid Substance Color Odor Taste Physical Melting Boiling State Point Point Chlorine Yellowish- Sharp, Sharp, Gas -101.6 -34.6 green suffocating sour Water Colorless Odorless tasteless Liquid 0.0 100.0 Sugar White Odorless Sweet Solid - Decom- poses bet 170- 186 Acetic Colorless Like sour Liquid 16.7 118.0 acid vinegar COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Changes in Matter 1. Physical change – a change in the physical property of matter, and no new substances is formed. The change was only in shape, amount or physical state. Ex.: melting of ice, heating of sand, evaporation of alcohol 2. Chemical change – a change in which there is a formation of new substances with different physical and chemical properties. Changes include substances burning, a mixture bubbling, a solid forming from solution, a change in color or odor or the release of heat or light energy. COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY Examples: rusting of iron, digestion of food, burning of wood Endothermic reaction – when heat is absorbed during the chemical reaction Exothermic Reaction – when heat is released during the chemical reaction. 3. Nuclear change – a change in the composition of the nuclei of an atom. Atomic fission – splitting of atoms Atomic fusion – combining of atoms COLLEGEOFPHARMACY UNIVERSITY OF PERPETUAL HELP – DR. JOSE G. TAMAYO MEDICAL UNIVERSITY COLLEGEOFPHARMACY