Physical Science Reviewer.pdf

Physical Science Reviewer (Q1) INTRODUCING PHYSICIANS Atomic Theory Timeline John Dalton (1766 - 1844) Solid Sphere (1803) - A british chemist and physicist...

Physical Science Reviewer (Q1) INTRODUCING PHYSICIANS Atomic Theory Timeline John Dalton (1766 - 1844) Solid Sphere (1803) - A british chemist and physicist who John Dalton proposed the Solid Sphere Model in Atoms are dense and solid, with no internal the early 19th century structure or subatomic particles considered. - Shifted from philosophical ideas to scientific theory Plum Pudding (1897) - First atomic model based on J.J. Thomson experimental evidence and Atoms are described as uniform, positively quantitative observations charged spheres with electrons embedded - Pave the way for the development of within them, similar to raisins in a pudding modern atomic theories Nuclear (1911) J.J. Thomson Ernest Rutherford - An English physicist known for his Atoms consists of a small, dense, positively work on nature of electrons who charged nucleus at the center, with proposed the Plum Pudding Model electrons orbiting around it, similar to in the last 19th century planets orbiting around the sun. - He discovered electrons as distinct particles Planetary (1913) - Shifted understanding from Neils Bohr indivisible atom to subatomic Electrons move in quantized, discrete particles energy levels around the nucleus and emit - Paved the way for further exploration or absorb energy when transitioning of atomic structure between levels. Ernest Rutherford Quantum (1902s) - A New Zealand-born physicist Erwin Schrodinger known for his contributions to Electrons do not have definite orbits, but are nuclear physics, who introduced the described by wave functions that represent Nuclear Model in the early 20th probability distributions of their locations. century - First model to proposed a central, massive nucleus - Explained the behavior of positively charged alpha particles in the gold foil experiment - Laid the groundwork for understanding atomic structure and radioactivity Niels Bohr - A Danish physicist known for his Nuclear Model (Ernest Rutherford) pioneering work in atomic structure, - Atoms have a nucleus with positive who proposed the Planetary Model charge and most of the mass, surrounded in the early 20th century by electrons that orbit like planets. It - He explained atomic spectra with explains why particles can pass through or precision bounce off atoms, and is the basis of our - Introduced the concept of quantized current understanding of atomic structure. energy levels Planetary Model (Neils Bohr) Erwin Schrodinger - Electrons orbit the nucleus of an atom in - An Austrain physicts renowned for specific energy levels or shells. This theory his contributions to quantum helped explain why atoms emit light and mechanics, who proposed the why they absorb certain colors of light. It Quantum Model in 1920s also helped explain the stability of atoms - Quantum mechanics provides a and why they dont fall apart. comprehensive understanding of electron behavior Quantum Model (Erwin - Schrodinger’s model successfully Schrodinger) explains multi-electron atoms - Electrons exist as a probable wave-like - Quantum mechanics is the pattern around the nucleus, not in a specific foundation of modern atomic theory orbit. It explains why electrons act like particles and waves, and is the foundation INTRODUCING ATOMIC MODELS of our understanding of atomic structure and widely used in modern physics. Solid Sphere Model (John Dalton) - Atoms are tiny balls that can’t be broken and are all made of the same material. This Intermolecular Forces - often abbreviated theory helped explain how different to IMH, are the attractive and repulsive chemicals mixed together and what makes forces that arise between the molecules of a them different substance. These forces mediate the interactions between individual molecules of Plum Pudding Model (J.J. a substance Thomson) - Atoms are like plum pudding, with tiny TYPES OF INTERMOLECULAR FORCE positive charges scattered throughout a 1. London Dispersion Forces (Van der cloud of negative electrons. This theory Waals) helped explain why atoms have a neutral 2. Dipole-Dipole interactions charge overall and why they emit light when 3. Ion-Dipole Interactions they collide with each other 4. Hydrogen Bonding - In the Plum Pudding Model, the “raisins” (electron) were thought to be scattered throughout the positive “pudding” (atom)  1. London Dispersion Forces Ionic Compounds - The weakest type of intermolecular force - A bond between metal and - Present in all molecules, even non-polar nonmetal. ones - The nonmetal attracts the electron, - Arises due to temporary dipoles caused by so it's like the metal donates its fluctuations in electron distribution electron to it. Example: Interaction between noble gas atoms (He, Ne). Rules in Naming Ionic Compounds Cation (metal): Name remains the 2. Dipole-Dipole Interactions same as the element (e.g., Na+ is - Occur in a polar molecules with permanent sodium) dipoles Anion (non-metal): Replace the - Positive end of one molecule attracts the ending with “-ide” (Chlorine to negative end of another Chloride) - Stronger than London dispersion forces Examples: Example: Interaction between HCI Formula Name 3. Ion-Dipole Interactions NO nitrogen monoxide - Occur between an ion and a polar molecule. Important in solutions where ionic N2O dinitrogen monoxide compounds dissolve in polar solvents Example: Sodium Chloride (NaCl) dissolved S2Cl2 disulfur dichloride in water Cl2O7 dichlorine 4. Hydrogen Bonding heptoxide - Special case of dipole-dipole interaction - Occurs when hydrogen is bonded to highly Covalent Compounds electronegative atoms (Nitrogen, Oxygen or - A bond between two nonmetals with Fluorine) similar electronegativities. Atoms - Strongest type of intermolecular force. share electrons in their outer Example: Water (H2O) molecules orbitals. Rules in Naming Covalent Compounds 1. Name the first element Compounds - It consists of atoms of two or 2. Name the second element changing more different elements bond together the end to “ide” 3. Prefixes - are used to denotes the THE TWO MAIN TYPES OF CHEMICAL number of atoms BONDING Examples: 1. Ionic Compounds PCl5 - Phosphorus pentachloride 2. Covalent Compounds SO2 - Sulphur dioxide CO2 - Carbon dioxide N2O5 - Dinitrogen pentaoxide  Mole (mol)- It is the SI unit for “amount of a substance” and is a unit quantity which refers to how much of an element of compound is present Molar mass - The atomic mass of an element is the weighted average value of the masses of the isotopes in a naturally occurring sample of the elements. Example of Criss-Cross Method: The Criss-Cross Method for Writing Chemical Formulas To write a correct formula for an ionic compound is to use the crisscross method. In this method, the numerical value of each of the ion charges is crossed Macromolecules over to become the subscript of the other ion. Molecule - It refers to very large molecules and something that consists of more than one atom. Herman Staudinger, coined it in 1920. Macromolecules are so huge that these are made up of more than 10,000 or more Types of Macromolecules 1. Carbohydrates 2. Nucleic Acids Examples: 3. Proteins 1. Ba+3 and Cl-1 4. Lipids Answer: BaCl3 2. Fe+3 and S-2 Answer: Fe2S3 Note: When you transpose the charges of each symbol, the final result of the symbol should be all positive.  - They help in the formation of the cell Carbohydrates membrane, formation of hormones, - The most abundant organic etc. molecules in nature - Carbohydrates are present in Hydrophilic - water loving humans, animal tissues, plant in Hydrophobic - water fearing microorganisms - Carbohydrates are also present in Types of Lipids tissue fluids, blood, milk, etc. 1. Neutral / True fats - They are triglycerides which are formed by Carbohydrates - are polymers of carbon, esterification of three molecules of hydrogen, and oxygen. They can be fatty acids with one molecule of classified as monosaccharides, trihydric alcohol, glycerol (glycerine disaccharides, and polysaccharides. or tri-hydroxy propane). - Carbohydrates are found in starch, 2. Simple Lipids - Waxes fruits, vegetables, milk, and sugars. Foods that are carbohydrates: Nucleic Acids - The nucleic acids include Fruit DNA and RNA that are the polymers of Quinoa nucleotides. Lentils Squash Nucleotides comprise a pentose group, a Brown or wild rice phosphate group, and a nitrogenous base Whole grain bread group. Sweet potatoes - All the hereditary information is Oatmeal stored in the DNA Beans DNA (Deoxyribonucleic acid) Whole wheat pasta - Double stranded Cereal - Can self replicate - Makes up genes which code for Remember: proteins is passed from one Monosaccharide - is any of the class of generation to another sugars or it is a simple sugar. RNA (Ribonucleic acid) Monosaccharide is the most basic form of - Single stranded carbohydrate. - Functions in actual synthesis of Fructose - type of fruit sugar proteins coded for by DNA Sucrose - disaccharide - Is made from the DNA template - Another term for sugar molecule Lipids - It is a hydrophobic set of DNA RNA macromolecules, i.e., they do not dissolve in A - Adenine A - Adenine water. T- Thymine U - Uracil - It involves triglycerides, carotenoids, C - Cytosine C - Cytosine phospholipids, and steroids. G - Guanine G - Guanine Proteins - Are the polymers of amino acids, These include the carboxylic and the amino group. There would be no lipids or carbohydrates without proteins because the enzymes used for their synthesis are the proteins themselves. PROTEINS - Collagen (skin) - Keratin (Hair) FOODS THAT ARE RICH IN PROTEIN - Eggs - Fish - Nuts - Beans