Fundational Chemistry Lecture Notes PDF

Official Business Fundational Chemistry Official Business Chemistry Chemistry is the branch of science that studies the composition and properties of matter and the changes that matter undergoes Official Business...

Official Business Fundational Chemistry Official Business Chemistry Chemistry is the branch of science that studies the composition and properties of matter and the changes that matter undergoes Official Business What Is Matter? Matter is anything that has mass and volume. A cup, pen, and eraser are made up of matter Official Business What Is Matter? The definition of matter is often taken to mean anything composed of atoms and molecules. Thus, matter is anything made of protons, neutrons, and electrons. Official Business Dalton’s atomic theory Dalton's atomic theory was the first complete attempt to describe all matter in terms of atoms and their properties. Postulates of Dalton’s Atomic Theory All matter is made up of tiny, indivisible particles called atoms. All atoms of a specific element are identical in mass, size, and other properties. However, atoms of different element exhibit different properties and vary in mass and size. Atoms can neither be created nor destroyed. Furthermore, atoms cannot be divided into smaller particles. Atoms of different elements can combine with each other in fixed whole-number ratios in order to form compounds. Official Business Dalton’s atomic theory Limitations of Dalton’s Atomic Theory It does not account for subatomic particles: Dalton’s atomic theory stated that atoms were indivisible. However, the discovery of subatomic particles (such as protons, electrons, and neutrons) disproved this postulate. It does not account for isotopes: As per Dalton’s atomic theory, all atoms of an element have identical masses and densities. However, different isotopes of elements have different atomic masses (Example: hydrogen, deuterium, and tritium). Official Business Law of conservation of Mass Law of definite composition Law of multiple Proportion Official Business Modern Atomic Theory 1. Matter is composed of exceedingly small particles called atoms. An atom is the smallest unit of an element that can participate in a chemical change. 2. An element consists of only one type of atom, which has a mass that is characteristic of the element and is the same for all atoms of that element. A macroscopic sample of an element contains an incredibly large number of atoms, all of which have identical chemical properties. 3. Atoms of one element differ in properties from atoms of all other elements. 4. A compound consists of atoms of two or more elements combined in a small, whole-number ratio. In a given compound, the numbers of atoms of each of its elements are always present in the same ratio 5. Atoms are neither created nor destroyed during a chemical change, but are instead rearranged to yield substances that are different from those present before the change Official Business The subatomic particles Electrons Protons Neutrons Official Business The subatomic particles Electrons J.J. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. Official Business Official Business The subatomic particles Protons Rutherford Gold foil Experiment – attributed to the discovery of nucleus Official Business The subatomic particles Protons Discovery of the Proton In 1886, Eugene Goldstein (1850-1930) discovered evidence for the existence of this positively charged particle. Using a cathode ray tube with holes in the cathode, he noticed that there were rays traveling in the opposite direction from the cathode rays Official Business Mass spectrometry is an analytical technique that is used to measure the mass-to-charge ratio of ions Official Business The subatomic particles Neutrons James Chadwick fired alpha radiation at beryllium sheet from a polonium source. This led to the production of an uncharged, penetrating radiation. Official Business (amu) Official Business Phases of Matter Matter is classified with the following phases or states Solid Liquid Gas Plasma Official Business Solid Solids have definite: Mass Volume Shape Official Business Liquid Liquids have definite Mass Volume No definite shape. Official Business Gas Gases have NO definite Mass Volume Shape Official Business QUESTIONS? Official Business