1ST-QUARTER-HANDOUT-IN-PHYSICAL-SCIENCE-1.pdf

Lesson I How the Elements found in the Universe were Formed? Big Bang-The early existence of the universe is believed to be the start of the occurrence of all matter. Approximately 13.8 billion years ago, light elements such as hydrogen, helium and a little of lithium emerged in the universe from th...

Lesson I How the Elements found in the Universe were Formed? Big Bang-The early existence of the universe is believed to be the start of the occurrence of all matter. Approximately 13.8 billion years ago, light elements such as hydrogen, helium and a little of lithium emerged in the universe from the Big Bang. Nucleosynthesis- the process that creates new atomic nucleus from pre-existing nucleons, which is proton and neutrons. Big Bang Nucleosynthesis- Refers to the process of producing the light elements. The origin of the light elements. (Lithium, Hydrogen, Helium, Hydrogen) Stellar nucleosynthesis is the process by which elements are formed in the cores and shells of the stars through nuclear fusion reactions. Nuclear fusion is a type of reaction that fuses lighter elements to form heavier ones. It requires very high temperatures and pressures. It is the reaction that fuels the stars since stars have very high temperatures and pressures in their cores. Stellar nucleosynthesis is the process by which elements are formed within stars by nuclear reactions. The abundances of these elements change as the stars evolve. Stellar evolution is the process by which a star changes over the course of time. Depending on the mass of the star, its lifetime can range from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. Alpha Ladder Process- One of two classes of the nuclear fusion reactions by which stars convert helium into heavier elements. Tri- Alpha Process- A process that consumes only helium, and produces carbon. Hydrogen Burning- Hydrogen is the lightest element and the most abundant in the universe. Thus, the formation of heavier elements starts with hydrogen. Hydrogen burning is the stellar process that produces energy in the stars. There are two dominant hydrogen burning processes, the proton-proton chain and carbon-nitrogen-oxygen (CNO) cycle. Proton-proton chain- is a series of thermonuclear reactions in the stars. It is the main source of energy radiated by the sun and other stars( Average stars). It happens due to the large kinetic energies of the protons. Carbon Nitrogen Oxygen Chain- For more massive and hotter stars, the carbon-nitrogen-oxygen cycle is the more favorable route in converting hydrogen to helium. Unlike the proton-proton chain, the CNO cycle is a catalytic process. Carbon12 acts a catalyst for the cycle. It is used in the initial reaction and is regenerated in the final one. Nucleosynthesis- is the process by which new nuclei are formed from preexisting or seed nuclei. Previously, you have learned about the types of nucleosyntheses. The big bang nucleosynthesis produced hydrogen and helium, whereas the stellar nucleosynthesis produced elements up to iron in the core of the stars. If the stellar nucleosynthesis produced only elements up to iron, then what type of nucleosynthesis produced the elements heavier than iron? The fusion reactions cannot produce nuclei higher than iron-56 because fusion reaction becomes unfavorable. This is because the nuclear binding energy per nucleon, the energy that holds the nucleus intact, decreases after iron-56. Therefore, different pathways are needed for the synthesis of heavier nuclei. Synthesis of heavier nuclei happens via neutron or proton capture processes. In neutron capture, a neutron is added to a seed nucleus. The addition of neutron produces a heavier isotope of the element. For Slow neutron capture or s-process happens when there is a small number of neutrons. Rapid neutron capture or r-process, on the other hand, happens when there is a large number of a neutron. The cosmic microwave background (CMB) is leftover radiation from the Big Bang or the time when the universe began. As the theory goes, when the universe was born it underwent rapid inflation, expansion and cooling. The CMB represents the heat leftover from the Big Bang. Lesson 2 How the Properties of Matter Relate to their Chemical Structure? Lewis valence dot diagrams, also called Lewis dot diagrams, are models that show only the valence electrons. Chemical Bond- A lasting attraction between atoms, ions, or molecules that enables the formation of chemical compounds. When atoms are chemically bond together, they share and transfer electrons. Ionic Bond (Electrovalent Bond)- Type of chemical bond formed from the electrostatic attraction between oppositely charged ions in chemical compound. This bond is formed by the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion. Ex. NaCl Covalent Bond- a covalent bond consist of mutual sharing of one or more pairs of electrons between two atoms. This bond is formed between atoms that have similar electronegativities—the affinity or desire for electrons. Because both atoms have similar affinity for electrons and neither has a tendency to donate them, they share electrons in order to achieve octet configuration and become more stable.Ex. HCl Polarity of Molecules The way atoms bond with one another is referred to as polarity. Polar Covalent- a molecule in which one end of the molecule is slightly positive, while the other end is slightly negative. Ex. HCl Nonpolar Covalent- type of chemical bond that is formed when electrons are shared equally between two atoms. Ex. CO2 Electronegativity is an expression of an atom’s tendency to attract electrons in a chemical bond. What about molecules with more than two atoms, such as H2O, CCl4, NH3, and CO2? The total molecular polarity is determined by both the bond polarity and the molecular shape in polyatomic compounds. The valence shell electron pair repulsion (VSEPR) theory would aid us in determining the spatial arrangement of atoms in a polyatomic molecule in terms of molecular geometry. The following steps can be used to determine a substance's form or molecular geometry: Step 1: Determine the molecule's central atom. The least electronegative element is the center atom. Step 2: For the molecule, draw the proper Lewis dot structure. Step 3: Count the number of bonding pairs and non-bonding (or lone pairs) electrons surrounding the center atom. Step 4: Using the total number of electron pairs, determine the electron pair orientation. Step 5: Name the shape depending on the atoms' positions. Intramolecular forces are the forces that hold atoms together within a molecule. Ex. NaCl, NH3 Intermolecular forces are the forces of attraction between neighboring molecules. Ion-dipole Interaction -The force of interaction between charged particles called ions and a polar molecule is known as the ion-dipole interaction. Characteristics of Ion-dipole forces: 1. The ions and dipoles are aligned closer to one another so that the forces are maximum. 2. They are stronger than the dipole-dipole forces. 3. They are weaker than the intramolecular ionic and covalent bond. Dipole-dipole Interaction - are attractive forces between the positive end of one polar molecule and the negative end of another polar molecule. These forces occur when the partially positively charged part of a molecule interacts with the partially negatively charged part of the neighboring molecule. Dipole-dipole interactions are the strongest intermolecular force of attraction. Ex. HCl---HCl Hydrogen Bond- It is a type of dipole-dipole interaction between the polar molecule Hydrogen and the highly electronegative elements Fluorine, Oxygen, and Nitrogen. Hydrogen bonding is a relatively strong force of attraction between molecules, and considerable energy is required to break hydrogen bonds. This explains the exceptionally high boiling points and melting points of compounds like water. Hydrogen bonding plays an important role in biology; for example, hydrogen bonds are responsible for holding nucleotide bases together in DNA and RNA. Ex. NH3---- H2O London- dispersion Interaction This intermolecular force of attraction can be found in all molecules. It is the weakest intermolecular force created by a non-polar molecule's transient dipoles. These are the weakest of the intermolecular forces and exist between all types of molecules, whether ionic or covalent—polar or nonpolar. The more electrons a molecule has, the stronger the London dispersion forces are. Ex. O2-----O2 Polarity of Molecules and their Properties The capacity of a certain material, the solute, to dissolve in a solvent is referred to as SOLUBILITY. It can be indefinitely soluble, like sugar in water, or poorly soluble, like silver chloride in water. INSOLUBILITY is a term used to describe chemicals that are poorly soluble. Solubility is a term that is frequently used in the context of solid solutes and liquid solvents. For covalent and ionic substances, the dissolving process, known as DISSOLUTION, is quite simple (polar & non-polar substances). When making a solution of water and salt, for example, the molecules and ions will interact. To achieve solubility, the substances must have the same polarity, as defined by the principle "LIKE DISSOLVES LIKE." As a result, polar chemicals dissolve in polar solvents, while nonpolar substances dissolve in nonpolar solvents. Miscibility is the property of two substances to completely mix to form a homogeneous solution. Usually the term is used to describe liquid mixtures, but it applies to solids and gases, too.Two substances are miscible if they mix in all proportions or concentrations to form a solution. In other words, it doesn’t matter whether you mix them equally or one component is present in a greater amount than the other. Ethanol and water are miscible liquids. No matter what proportions are mixed, they form a solution. Benzene and acetone are miscible. All gases are miscible with each other at normal pressures. For example, helium and nitrogen gases are miscible. Air and argon are miscible. Ethanol vapor and water vapor are miscible. Miscible solids work a bit differently because they form from liquid melts and then solidify. Elements that form alloys are miscible. So, iron and carbon are miscible (to make steel). Copper and zinc are miscible (to make brass). Immiscibility is the property where two substances are not capable of combining to form a homogeneous mixture. The components are said to be "immiscible”. Components of an immiscible mixture will separate from each other. The less-dense fluid will rise to the top; the more-dense component will sink. Oil and Water. Kerosene and Water. Corn Syrup and Vegetable Oil. Gasoline (Petrol) and Water. Wax and Water. Simple Collision Theory- This theory states that for reactions to occur, molecules, atoms, or ions must first collide. To collide is to bump into each other or touch each other with great force. Not all collisions are successful. For collisions to be effective, particles must possess the minimum amount of energy needed for the reaction and particles must collide with the proper orientation. In 1916 and 1918, Max Trautz and William Lewis separately proposed the Collision Theory which established how chemical reactions initiate change. According to the collision theory, a chemical reaction can only occur upon following a specific set of conditions, namely: 1. the molecules should collide to react;  2. the collision of molecules should be in the proper orientation; and 3. that the colliding molecules should have enough energy to react. 1. The molecules should collide to react. Solids send waves to each other liquids slip over and gases move freely in different spots. These continuous movements of molecules enable them to collide with each other. 2. The collision of molecules should be in the proper orientation. The colliding species must be oriented in a manner favorable to the necessary rearrangement of atoms and electrons. The orientation of a molecule is very important for a chemical reaction to take place. And as moving molecules bounce off from the walls of their container or have an inert collision with other molecules, their orientation may change. 3. The colliding molecules must have enough energy to react. Endothermic or endergonic reaction happens when the energy is absorbed in the formation of the products in the chemical reaction. The figure on the right shows that the energy of the reactants is less than the energy of the products in the chemical reaction. Exothermic or exergonic happens when energy is released in the formation of the products. The figure on the right shows that the energy of the reactants is greater than the energy of the products of the chemical reaction. Chemical reactions need a minimum energy requirement for them to proceed, and this is called activation energy (Ea). Activation energy serves as the minimum amount of energy for a chemical reaction to occur. If two reacting molecules collide with one another and the energy of the collision is equal to or greater than the activation energy, then the chemical reaction will take place. Factors Affecting Reaction Rates These factors include the concentration of reactants, temperature of the system, and exposed surface area/ particle size. Concentration of Reactants -The rate of chemical reactions are usually directly proportional to the reactants’ concentration; meaning, the higher their concentration, the faster the rate of reaction will be. Concentration refers to the amount of substance per unit volume. For example, using 1 tablespoon of Zonrox will whiten clothes better than using 1 teaspoon of the same Zonrox in the same amount of water. In collision theory, an increase in reactant concentration ensures that there will be more collisions between particles. This also increases the probability rate of effective collisions. Temperature - is defined as the measure of the average kinetic energy of the molecule. In Collision Theory, increasing the temperature of the reactants increases the kinetic energy that they possess. For example, boiling water cooks faster than warm water. The water molecules colliding in the boiling water have higher kinetic energy than the molecules in warm water. This higher kinetic energy increases the rate of chemical reaction and reaches the activation energy required for it to take place. The reaction in the example is cooking. Surface Area/Particle Size – Surface area refers to the exposed area of a substance. In collision theory, an increase in surface area relates to more particles being available for collision. An example will be the rate of melting of samples of ice with the same mass but are of different size of particles. Subsequently, the smaller the particle size of the substance, the bigger its surface area. Catalysts are substances that increase reaction rate without being consumed in the chemical reaction. The presence of catalysts allows the reaction to occur requiring lower activation energy. Examples of catalyst are the enzymes in the human body. The digestive enzyme and gastric juice, for example, helps in the breaking down of food in the stomach. The same gastric juice can be used again at another time because it was not consumed during the chemical reaction of digestion. Catalysts provide an alternative reaction pathway for the process of bond breaking, resulting in lower activation energy which leads to higher rates of the chemical reaction. It means that the energy barrier allows more reacting molecules to be converted into products, thereby speeding up the reaction. Note that catalysts do not affect the composition of the equilibrium but only affect the rate at which this equilibrium has reached. LIMITING REACTANT and the AMOUNT of PRODUCTS FORMED The limiting reactant or limiting reagent is a reactant in a chemical reaction that determines the amount of product formed. The reactant present in the lower amount would be limiting reactant. All of it would be used up before the other reactant ran out. Excess reactant- The excess reactant is the reactant in a chemical reaction with a greater amount than necessary to react completely with the limiting reactant. It is the reactant(s) that remain after a chemical reaction has reached equilibrium. STEPS IN SOLVING THE LIMITING REACTANT AND EXCESS REACTANT 1.Convert the mass of both reactants to their corresponding moles. 2. Compute the number moles of product that can be formed from each reactant. 3. Compare the number of moles of product formed from each reactant. 4. Identify the reactant that gives a lower amount of product as the limiting reactant. 5. Identify the reactant that gives a higher amount of products as the excess reactant. Biological Macromolecules - chemical building blocks of living organisms. It plays a critical role in cell structure and function. Most biological macromolecules are polymers which are any molecules constructed by linking together many smaller molecules called monomers. Examples of monomers and polymers can be found in the sugar you might put in your coffee or tea. Biological macromolecules all contain carbon in ring or chain form, which means they are classified as organic molecules. They usually contain hydrogen and oxygen, as well as nitrogen and additional minor elements. FOUR CLASSES OF BIOLOGICAL MACROMOLECULES Carbohydrates Lipids Protein Nucleic Acids CARBOHYDRATES - The origin of the term carbohydrate is based on its components: carbon (carbo) and water (hydrate) Benefits of Carbohydrates Carbohydrates are your body's main source of energy: They help fuel your brain, kidneys, heart muscles, and central nervous system. For instance, fiber is a carbohydrate that aids in digestion, helps you feel full, and keeps blood cholesterol levels in check. Your body can store extra carbohydrates in your muscles and liver for use when you're not getting enough carbohydrates in your diet. A carbohydrate-deficient diet may cause headaches, fatigue, weakness, difficulty concentrating, nausea, constipation, bad breath and vitamin and mineral deficiencies. Carbohydrates are classified into 3 subtypes: Monosaccharides Disaccharides Polysaccharides Monosaccharides are classified based on the position of their carboxyl group and the number of carbons in the backbone. Common Monosaccharides 1. Glucose- an important source of energy. 2. Galactose- milk sugar 3. Fructose- found in fruits Disaccharides- Form when two monosaccharides undergo a dehydration reaction. During this process, the hydroxyl group of one monosaccharide combines with the hydrogen of another monosaccharide, releasing a molecule of water and forming a covalent bond. Common Disaccharides 1. Lactose- is a disaccharide consisting of the monomers glucose and galactose. 2. Maltose- malt sugar, is a disaccharide formed by a dehydration reaction between two glucose molecules. 3. Sucrose or table sugar- the most common disaccharide which is composed of the monomers glucose and fructose. Polysaccharides- A long chain of monosaccharides link by glycosidic bond. (is a type of covalent bond that joins a carbohydrate molecule to another group) The chain may be branched or unbranched, and it may contain different types of monosaccharides. Glycogen- is the storage form of glucose in humans and other vertebrates. Cellulose- the cell wall of plants mostly made up of cellulose. It’s made up of glucose monomers. Starch- is the stored form of sugars in plants and is made up of glucose monomers. The excess glucose is stored as starch in different plant parts. Functions of Carbohydrates Provides energy to the body, particularly though glucose, a simple sugar that is found in many basic food. Carbohydrates contain soluble and insoluble elements. As an immediate source of energy, glucose is broken down during the cellular respiration, which provides ATP, the energy currency of the cell. LIPID MOLECULES - (from the Greek word lipos which means “fat”) are macromolecules which are highly insoluble in water. - Fats and oils, which may be saturated or unsaturated, can be healthy but also serve important functions for plants and animals. Important Groups of Lipids Fats Phospholipids Steroids FATS- Provide energy and insulation for many organisms. Fats may be saturated or unsaturated. Saturated Fats- If there are only single bonds between neighboring carbons in hydrogen chain, the fat is said to be saturated. Saturated fats are solid in room temperature. These fats tend to come from food like red meat, cheese, and butter. Unsaturated Fats- Are usually of plant origin and contain cis unsaturated fatty acids. Unsaturated fats are liquid at room temperature. These fats tend to come from food like nuts, vegetable and fish. Types of Unsaturated Fats Monounsaturated Fats Polyunsaturated Fats Monounsaturated Fats- Fatty acids that have one double bond in the fatty acid chain. Monounsaturated fats occurs mostly in plant oil. Polyunsaturated Fats - Are fats in which the constituent hydrocarbon chain possesses two or more carbon-carbon double bonds. Polyunsaturated fats are found in plant foods and some fish. Trans Fats- Form of unsaturated fat associated with the number of negative health effects. Cis Fats - Generally good for health unless consumed in unreasonably high quantities. Essential Fats - Omega-3 fats and Omega-6 fats are essential for human biological processes, but they must be ingested in the diet because they cannot be synthesized. PHOSPHOLIPIDS -major components of the plasma membrane, the outermost layer of the animal cell. The fatty acid tails of the phospholipids face outside, and the phosphate heads face the outward aqueous side. STEROIDS- Are lipids because they are hydrophobic and insoluble in water. One important steroid is cholesterol. Steroids include cholesterol, chlorophyll, and hormones. Cholesterol is the most common steroid and is mainly synthesized in the liver. Importance of Lipids Stores energy in the body for further use. They serve as insulating materials against heat loss, protecting the body and its vital parts from mechanical injury. Fats contain twice the amount of energy found in carbohydrates. It also makes up the membrane of cells and form water- proof coverings on plants and animals. Proteins- Are complex molecule composed of one or more chains of amino acids linked by peptide bonds. Amino acids- are molecules used by all living things to make proteins. Your body needs 20 different amino acids to function correctly. Nine of these amino acids are called essential amino acids. Essential amino acids must be consumed through the food you eat. Essential amino acids can be found in a variety of foods, including beef, eggs and dairy. Proteins are macromolecules which are made up of carbon, hydrogen, oxygen, nitrogen and often sulfur. Proteins have different shapes and molecular weights, depending on the amino acid sequence. Type of Proteins Enzymes Hormones Enzymes- Are proteins that catalyzed biochemical reactions. They help speed up chemical reactions in our body. These enzymes are essential for chemical processes like digestion and cellular metabolism. Substrate- The reactants that undergo the chemical reaction catalyzed by the enzyme. Active Site- Location where substrate bind to or interact with the enzyme. Two Basic Classes of Enzymes Catabolic Enzymes Anabolic Enzymes Catabolic Enzyme- Enzymes that break down their substrate. Example: Glycolysis and Krebs Cycle Anabolic Enzymes- Enzymes that build up more complex molecules from their substrates. Example: DNA Replication Enzymes are essential for digestion. Enzymes are also essential for biosynthesis. Hormones- Chemical-signaling molecules. These proteins are secreted by endocrine cells that act to control or regulate physiological processes. Functions of Enzymes 1. Catalyses chemical reaction. 4. Responding to stimuli 2. Synthesizing and repairing DNA. 5. Providing structural support. 3. Transporting materials across the cell. 6. Receives and sends chemical signals. Nucleic Acid- are important because they make up genetic information in living things. There are two types of nucleic acid and they are DNA and RNA. Nucleic acids are key macromolecules in the continuity of life. They carry the genetic blueprint of a cell and carry instructions for the functioning of the cell. The two main types of nucleic acids are; Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA). DNA - is the genetic material found in all living organisms, ranging from single-celled bacteria to multicellular mammals. DNA is the basic instructions for living things. It is passed down from parent to offspring and is found in the nucleus of the cell. The sugar and phosphate make up the backbone, while the nitrogen bases are found in the center and hold the two strands together. The nitrogenous bases can only pair in a certain way: A pairing with T and C pairing with G. This is called base pairing. Nitrogenous bases are organic molecules and are so named because they contain nitrogen and carbon. RNA is the nucleic acid that makes proteins from the code provided by DNA through the processes of transcription and translation. The nitrogen bases in RNA include Adenine (A), Guanine (G), Cytosine (C), and Uracil (U). RNA is made up of monomers called nucleotides. Each nucleotide is made up of 3 components a nitrogenous base, a pentose (five carbon) sugar called ribose and a phosphate group. Importance of Nucleic Acid Nucleic acids are the only way a cell has to store information on its own processes and to transmit that information to its offspring. When nucleic acids were discovered to be the carriers of hereditary information, scientists were able to explain the mechanism for Darwin and Wallace's theory of evolution and Mendel's theory of genetics. By understanding nucleic acids and their mechanics of action, we can understand how diseases occur and, eventually, how to cure them.