Lesson 5: Corpuscles to Chemical Atomic Theory PDF

LESSON 5: CORPUSCLES TO CHEMICAL ATOMIC THEORY (THE DEVELOPMENT OF ATOMIC THEORY) How did they came up with these IDEAS? OBJECTIVES: Discuss the development of atom and element from Robert Boyle to John Dalton, Discuss the aspects of Chemical Atomic Theory, and relate evid...

LESSON 5: CORPUSCLES TO CHEMICAL ATOMIC THEORY (THE DEVELOPMENT OF ATOMIC THEORY) How did they came up with these IDEAS? OBJECTIVES: Discuss the development of atom and element from Robert Boyle to John Dalton, Discuss the aspects of Chemical Atomic Theory, and relate evidence (3 Fundamental Laws) to these aspects; and Gain an appreciation of the scientists involved in the development of the science of Chemistry They played crucial roles in laying the groundwork for MODERN ATOMIC THEORY.  -proposed that matter was 17th Century composed of various combinations of different particles, which he called… -as minute CORPUSCLES particles that make up matter. -these corpuscles are not indivisible but can be divided into smaller parts. -possess definite shapes and sizes and are capable of motion. Boyle’s corpuscularian hypothesis suggested that all matter is composed of these small particles, which differ only in shape and motion.  Some of his IDEAS - CORPUSCLES were “certain primitive and simple, or perfectly unmingled bodies” that were indivisible and whole. This went against the Aristotelian thinking that objects are made of divisible elements. It was more like the ideas of Democritus and Leucippus. - He recognized elements as the simplest substances that constitute mixtures, and that elements are those that cannot be decomposed into other substances via chemical reactions. - He emphasized the need to observe and test the presence of corpuscles in alchemical experiments.  1789 Conducted lots of experiment using closed vessels and precise weight measurement. French Chemist  1789 —He disproved the principle of PHLOGISTON - where Metals, which gain weight when heated in open air, actually react with oxygen air, heated metals were thought causing it to form a calx (metal oxide) to lose a substance of negative weight. By looking at the air from reacting metals —He showed that AIR is not an and calces, he found different “types” of air, element because it could be one of which caused burning to happen. separated into several Lavoisier called it OXYGEN. components. —He showed that WATER is Oxygen was found to produce water when burned in the presence of “flammable air” (a not an element, because it part of air that would be later called was made of two substances. hydrogen).a  —FATHER OF MODERN CHEMISTRY —He refute Aristotle’s thinking of a universe composed of four elements. —He defined Chemical Element as a substance that cannot be broken down into simpler components. —He defined COMPOUND as a substance composed of there elements. —He wrote the first Chemistry Textbook —He made an initial list of 33 ELEMENTS, and created a systematic way of naming elements and the compounds they French Chemist created. Antoine Lavoisier listed 33 substances as elements in his 1789 work, Traité Élémentaire de Chimie. Here are the elements he identified: 1.Light 17. Gold 2.Caloric (heat) 18. Iron 3.Oxygen 19. Lead 4.Azote (nitrogen) 20. Manganese 5.Hydrogen 21. Mercury 6.Sulphur 22. Molybdena (molybdenite) 7.Phosphorus 23. Nickel 8.Charcoal (carbon) 24. Platina (platinum) 9.Muriatic radical (chloride) 25. Silver 10.Fluoric radical (fluoride) 26. Tin 11.Boracic radical (borate) 27. Tungstein (tungsten) 12.Antimony 28. Zinc 13.Arsenic 29. Lime (calcium oxide) 14.Bismuth 30. Magnesia (magnesium oxide) 15.Cobalt 31. Barytes (barium sulfate) 16.Copper 32. Argill (clay or alumina) 33. Silex (silica)  He further developed the concept 1766-1844 of atom by merging it with element, and formally established the two in the practice of chemistry. Chemical Atomic Theory ❖ Gases, and all chemically inseparable elements, are made of ATOMS. ❖ The atoms of an element are identical in their masses. ❖ Atoms of different elements have different masses. ❖ Atoms combine in small, whole number ratios. Note: The CHEMICAL ATOMIC THEORY was proposed as the best explanation to the THREE IMPORTANT OBSERVATIONS Law of made at that time. Conservation of Mass Law of Definite Law of Multiple Proportion Proportion  Law of Law of Law of Definite 3 Fundamental Laws Conservation Proportion Multiple Proportion of Mass The Law of Conservation of Mass, formulated by Antoine Lavoisier in 1789, -states that mass is neither created nor destroyed in a chemical reaction. This principle implies that the total mass of the reactants in a chemical reaction is equal to the total mass of the products. Lavoisier demonstrated this by carefully measuring the mass of substances before and after chemical reactions, showing that any apparent loss or gain in mass was due to gases that were either released or absorbed. This law laid the foundation for modern chemistry by emphasizing the importance of precise measurement and the concept of mass balance in reactions.  Law of Law of Law of 3 Fundamental Laws Conservation Definite Multiple of Mass Proportion Proportion ▪ was first proposed by Joseph Proust in 1797 ; also known as Proust’s Law, ▪ states that a given chemical compound always contains its component elements in a fixed ratio by mass, regardless of its source or method of preparation. For example, water (H₂O) always consists of hydrogen and oxygen in a mass ratio of approximately 1:8, meaning that for every 1 gram of hydrogen, there are 8 grams of oxygen.  Law of Law of Law of 3 Fundamental Laws Conservation Definite Multiple of Mass Proportion Proportion formulated by John Dalton himself. states that when two elements form more than one compound, the ratios of the masses of the second element that combine with a fixed mass of the first element are simple whole numbers. ▪ That elements were made of the same atoms and had properties unique to the element, while chemical compounds were made of different combined or compounded atoms, and exhibited different sets of properties. ▪ That one could compute the weights of elements (and their atoms)by looking at the comparable amounts that they formed. ▪ That one could compute the atomic weights compared to a reference. Given the technology that time, the NUMBER of ATOMS in different compounds was not known. FOR EXAMPLE: Water was known to be formed from hydrogen and oxygen, BUT, not in the ratio 2:1, so many calculations of atomic weight were inaccurate. SCIENTIST WHO MADE HEADWAY IN THE CONCEPT OF ELEMENTS BECAUSE OF DALTON’S THEORY JOSEPH GAY-LUSSAC AMEDEO AVOGADRO DMITRI MENDELEEV JOSEPH GAY-LUSSAC He determined that OXYGEN GAS was made of 2 atoms of OXYGEN and took the form of molecule instead of atom. This offered the possibility that an element wasn’t necessarily made up of 1 atom, thus distinguishing ATOM from MOLECULE.  Avogadro’s Hypothesis (1811): AMEDEO AVOGADRO -Molecules in Gases: Avogadro suggested that gases are composed of molecules, which can consist of two or more atoms. This was a departure from Dalton’s idea that atoms were the smallest units. -Equal Volumes, Equal Molecules: Avogadro’s law states that equal volumes of gases, at the same temperature and pressure, contain an equal number of molecules. Avogadro’s work helped clarify the distinction The man who between atoms and molecules, which was not clear in conceptualize Dalton’s theory. This was crucial for understanding the the MOLE. behavior of gases and the composition of compounds.  Molecules in Gases Dalton: Proposed that atoms are the smallest indivisible particles of matter and that atoms of the same element are identical in mass and properties. Dalton believed that gases were made up of individual atoms. Avogadro: Introduced the concept of molecules, suggesting that gases are composed of molecules, which can consist of two or more atoms. This was a significant shift from Dalton’s idea of indivisible atoms  Equal Volumes, Equal Molecules Dalton: Did not make a distinction between atoms and molecules, leading to confusion about the behavior of gases. Avogadro’s Law: Stated that equal volumes of gases, at the same temperature and pressure, contain an equal number of molecules. This clarified the relationship between volume and the number of particles in gases. DMITRI MENDELEEV —He published a periodic table of elements that ordered elements according to their atomic weights. —He noted patterns in their properties that enabled him to predict the discovery of other elements. —His table became the basis of the Modern Periodic Table of Elements. Three Fundamental Laws of Chemistry | Dalton's Atomic Theory (chemistrynotes.com) 2.2 Fundamental Chemical Laws - Chemistry LibreTexts Atomic theory | Definition, Scientists, History, & Facts | Britannica Atomic Theory – Introductory Chemistry – 1st Canadian Edition (opentextbc.ca) John Dalton: Unveiling the Father of Modern Atomic Theory (historydata.com)