1-HISTORY OF CHEMISTRY & PARTICULATE NATURE OF MATTER.pdf

CHEMISTRY: THE SCIENCE OF MATTER  CHEMISTRY - The Science of Matter - Deals with the structure and composition of matter - Deals with the changes that matter undergoes and the energy involved that accompanies these changes WHAT ARE YOUR DAILY ACTIVITIES WHI...

CHEMISTRY: THE SCIENCE OF MATTER  CHEMISTRY - The Science of Matter - Deals with the structure and composition of matter - Deals with the changes that matter undergoes and the energy involved that accompanies these changes WHAT ARE YOUR DAILY ACTIVITIES WHICH INVOLVE CHEMISTRY?  AGRICULTURE: Fertilizers, pesticides COSMETICS: MEDICINE: Perfume, Imaging, drugs, cosmetics prosthesis ELECTRONICS MILITARY: : CHEMISTRY Guns, gunpowder, Semiconductor, insulator vests COMPUTER EDUCATION: TECHNOLOGY: Papers, ink, Computer pens, and chips, other SPORTS: hardware materials Equipment, energy drink PURE CHEMISTRY APPLIED CHEMISTRY - gathers knowledge - using chemistry to for the sake of attain certain goals in knowledge specific fields that lead to applications and production of new materials  BRANCHES OF CHEMISTRY 1. INORGANIC CHEMISTRY - Deals with the study of all elements and their compounds except the element carbon 2. ORGANIC CHEMISTRY - Deals with the study of carbon compounds, specifically hydrocarbons, and their derivatives  BRANCHES OF CHEMISTRY 3. BIOCHEMISTRY - Deals with the study of compounds present in living organisms and their interaction with one another 4. PHYSICAL CHEMISTRY - Deals with the study of physical processes in chemical reactions  BRANCHES OF CHEMISTRY 5. ANALYTICAL CHEMISTRY - Deals with the study of what and how much substance is present in a particular sample of matter 6. NUCLEAR CHEMISTRY – Deals with radioactivity, nuclear processes, and nuclear properties HISTORY OF CHEMISTRY ANCIENT MESOPOTAMIANS AND BABYLONIANS - Chemistry as the art of brewing wine/fermented beverages, extracting metals from ores, perfume making ANCIENT EGYPTIANS - Chemistry as an art of embalming, cosmetics, and the making of paper-like plant-based (papyrus) writing sheet ANCIENT EGYPTIANS Alchemy- Khemia, the Greek word for Egypt then the Arabs in the 7th Century, added 'al-' to the word Khemia meaning 'the Black Land’ - developed the tools and techniques for working with chemicals - Application of chemistry to medicine, namely iatrochemistry Alchemy has two sides: Practical: techniques for working with metals, glass, dyes, etc. Mystical: concepts like perfection – gold was a perfect metal. Transformation of a substance to fit a purpose. ANCIENT CHINESE - used copper to cast matter which products range from weapons to daily living articles ANCIENT CHINESE - use of various concoctions known as alchemical medicines or elixirs Ex. realgar (As4 S4 )- utilized as a disinfectant for treating acne, “silver paste”- made from mercury, silver, and tin, which was used to fill a tooth ANCIENT CHINESE - Invention of true paper by Cai Lin (silk, bamboo) - Discoveries of gunpowder in the Tang Dynasty (618– 907 AD) mixture of sulfur, charcoal, and potassium nitrate ANCIENT GREEKS AND ROMANS - Chemistry as an art of making alloys - Chemistry as an art of philosophy DEMOCRITUS ARISTOTL E  DEMOCRITUS “The universe is composed of two elements: the atoms and the void in which they exist and move.”  ARISTOTLE “The matter was composed of four elements: earth, fire, air, and water. An Experimental Approach on Chemistry: The Scientific Method  An Experimental Approach: The Scientific Method In the 1500s, a shift started from alchemy to science – King Charles II was a supporter of the sciences “Royal society of London for the promotion of natural knowledge” Encouraged scientists to use more experimental evidence and not philosophical debates  An Experimental Approach: The Scientific Method Science is much different from philosophy because it uses observation and experimentation to form conclusions about how the universe works. All ideas in science are constantly being tested, evaluated, revised, and re-tested. MODERN CHEMISTRY 16TH CENTURY- Chemistry as analytical science Robert Boyle – 1st true “chemist”, - Sceptical chymist, 1661 - Boyle called the substances that cannot be broken down into other substances elements - Discovered a relationship between pressure and volume (Boyle’s Law) MODERN CHEMISTRY Joseph Priestly – discovers oxygen MODERN CHEMISTRY Antoine Lavoisier – Matter cannot be created or destroyed, Law of Conservation of Mass - Role of oxygen in Combustion reaction MODERN CHEMISTRY Henry Cavendish – discovered hydrogen MODERN CHEMISTRY Joseph Louis Proust – Found that a given compound always contains exactly the same proportion of elements by mass, the Law of Definite Proportion or Law of Constant Composition MODERN CHEMISTRY John Dalton The ratios of the masses of elements in a compound can always be reduced to small whole numbers Dalton’s Atomic Theory 1) all matter is composed of tiny particles called atoms 2) the atoms of an element are always identical while the atoms of different elements are different Dalton’s Atomic Theory 3) compounds form when atoms combine; atoms combine in small whole-number ratios 4) reactions involve the reorganization of atoms; the atoms themselves do not change PARTICULATE NATURE OF MATTER DEMOCRITUS Matter is made up of small & indivisible particles called atomos STATES OF MATTER - Solid, Liquid, Gas - Inter-convertibility depends on pressure and temperature  SOLID MACROSCOPIC VIEW MICROSCOPIC VIEW - Definite shape and - Particles are very much definite volume close to each other  LIQUID MACROSCOPIC VIEW MICROSCOPIC VIEW - Indefinite shape, - Particles are slightly definite volume loose, has weak force of attraction  GAS MACROSCOPIC VIEW MICROSCOPIC VIEW - Indefinite shape, - Particles are very far indefinite volume from each other  PHASE CHANGE SUBSTANCES AND MIXTURES Substance- definite or constant composition and distinct properties. Ex. Water, salt, and carbon dioxide Mixture- a combination of two or more substances in which the substance retains its distinct properties. It does not have a constant composition SUBSTANCES AND MIXTURES Mixture Homogeneous mixture- the composition of the mixture is the same throughout the solution Heterogeneous mixture- the composition is not uniform  ELEMENTS AND COMPOUNDS Elements- substances that cannot be separated into simpler substances by chemical means. It is composed of one type of atom.  ELEMENTS AND COMPOUNDS Compound- a substance composed of two or more elements chemically united in fixed proportions. It can be separated only by chemical means into their pure components PHYSICAL PROPERTIES OF MATTER - Properties that retain the identity of matter 1. Intensive /Intrinsic Physical Properties – constant regardless of the amount of matter ( boiling point, melting point, density, color, odor, texture) PHYSICAL PROPERTIES OF MATTER - Properties that retain the identity of matter 2. Extensive /Extrinsic Physical Properties – not constant and change with the amount of matter present ( shape, size, length, mass, volume) CHEMICAL PROPERTIES OF MATTER - Tend to change the identity of matter - Flammability, ability to change color upon exposure to air, ability to form bubbles when heated