Chemistry notes - Pure Substance: Contains one type of particle Elements: Pure substance that cannot be broken down by further chemical or physical means Cannot be converted into a simpler form Compound Pure substance obtained by mixing two or more different types Water: Compound of hydrogen and oxygen Chemically bound, only decomposes chemically physical Mechanical mixture Solution Chemistry: Describes the ability of a substance to react with another substance to form one or more new substances Reacts with water Calcium carbide reacts with water to form acetylene Gases Reacts with oxygen Aluminum reacts with oxygen and forms a layer Oxidation Aluminum Reactivity with Acids Baking soda and sodium bicarbonate reacts with acids, produces Carbon Dioxide gas Reaction with other pure chemicals Flammability (ability of 4 things to burn in 4) Stability ▪ How does the chemical decompose Toxicity ▪ Risk of exposure to animals and plants. Atom - The smallest particle of the element holding the main element Dalton's Atomic Theory
- All matter is made up of tiny particles called atoms - Atoms cannot be created, destroyed or divided into smaller particles - All the same atoms. are the same in size and mass - atoms of one element are different in size and mass from atoms of other elements - compounds are formed when atoms of different elements come together in certain proportions and come together in certain proportions Electrons and Protons: - When Applies to gas as the same electric current from different gas, electric current comes from negative electrons - 1897 Discovered by Thomson - Same negative particles discovered in atoms - pp. A subatomic particle found and studied - Thomson described the atom as a positively charged block of material in which negative electrons were released Core: - Ernest Rutherford Experimenting with alpha particle from a gold piece of paper and thinking about what it is, he said he saw alpha - Thomson's atomic model failed to provide an explanation for this observation. It can only be predicted that each of the particles will move as fast as an alpha particle.