Chapter 4.pptx

Because learning changes everything. ENVIRONMENTAL SCIENCE A Study of Interrelationships, 16th Edition Chapter 4 Interrelated Scientific Principles: Matter, Energy, and Environment Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consen...

Because learning changes everything. ENVIRONMENTAL SCIENCE A Study of Interrelationships, 16th Edition Chapter 4 Interrelated Scientific Principles: Matter, Energy, and Environment Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. ® Because learning changes everything. 4.1 The Nature of Science Science is a process used to solve problems or develop an understanding of nature that involves testing possible answers. The scientific method is a way of gaining information (facts) about the world by forming possible solutions to questions, followed by rigorous testing to determine if the proposed solutions are valid. ® Because learning changes everything. Basic Assumptions in Science Specific causes exist for observed events. These causes can be identified. General rules or patterns can be used to describe observations. Repeated events probably have the same cause. Perceptions are not individualistic. Fundamental rules of nature are universal. ® Because learning changes everything. Cause-and-Effect Relationships Scientists distinguish between situations that are merely correlated (happen together) and those that are correlated and show cause-and-effect relationships. Correlation ≠ Causation! ® Because learning changes everything. Elements of the Scientific Method 1 The scientific method requires a systematic search for information and continual evaluation to determine if previous ideas are still supported. Scientific ideas undergo constant reevaluation, criticism, and modification. ® Because learning changes everything. Elements of the Scientific Method Access the text alternative for slide images. 2 ® Because learning changes everything. Elements of the Scientific Method 3 Observation occurs when we use our senses or extensions of our senses to record an event. Scientists refer to observations as careful, thoughtful recognitions of events. Observations often lead to additional questions about the observations. The way questions are asked will determine how one goes about answering them. Exploring other sources of knowledge is the next step to gain more information. ® Because learning changes everything. Elements of the Scientific Method 4 A hypothesis is a testable statement that provides a possible answer to a question, or an explanation for an observation. A good hypothesis must be logical, account for all relevant information currently available, allow prediction of related future events, and be testable. Given a choice, the simplest hypothesis with the fewest assumptions is the most desirable. ® Because learning changes everything. Elements of the Scientific Method 5 An experiment is a re-creation of an event that enables an investigator to support or disprove a hypothesis. A controlled experiment divides the experiment into two groups (experimental and control) that differ by only one variable. Reproducibility is important to the scientific method. A good experiment must be able to be repeated by independent investigators to ensure a lack of bias. ® Because learning changes everything. Elements of the Scientific Method 6 When broad consensus exists about an area of science, it is known as a theory or law. A theory is a widely accepted, plausible generalization about fundamental scientific concepts that explains why things happen. A scientific law is a uniform or constant fact of nature that describes what happens in nature. ® Because learning changes everything. Elements of the Scientific Method 7 Communication is a central characteristic of the scientific method. An important part of the communication process involves the publication of articles in scientific journals about one’s research, thoughts, and opinions. This provides other scientists with an opportunity to criticize, make suggestions, or agree. ® Because learning changes everything. Elements of the Scientific Method Observation 8 Communication Scientific inquiry often begins with an observation that an event has occurred. ©McGraw-Hill Education/John Thoeming, photographer ® Because learning changes everything. 4.2 Limitations of Science Scientists struggle with the same moral and ethical questions as other people. It is important to differentiate between data collected during an investigation, and scientists’ opinions of what the data mean. It is important to recognize that scientific knowledge can be used by different people to support opinions that may not be valid. ©Gary Gladstone/Stockbyte/Getty Images RF ® 4.3 Pseudoscience Because learning changes everything. Pseudoscience is a deceptive practice that uses the appearance or language of science to convince, confuse, or mislead people into thinking that something has scientific validity when it does not. Why it is NOT science Scientists gather evidence and form hypotheses to support their evidence. They test their hypotheses by doing many repeated experiments. They eventually publish scientific journals, where their work is peer reviewed and are only accepted if they are confirmed by independent laboratories. ® society? Because learning changes everything. Spread of misinformation People widely believing what they read Takes a toll on certain individuals ® Why is pseudoscience bad for society? Because learning changes everything. Spread of misinformation People widely believing what they read Takes a toll on certain individuals Examples of some pseudosciences: Vaccine denialism (antivaccine activism) Crystals and homeopathic remedies HIV doesn’t cause AIDS Cures for Covid-19… Cow urine? Cocaine? Bleach? ® ronment Because learning changes everything. Global warming is a hoax Denial of climate change ® Because learning changes everything. ENVIRONMENTAL SCIENCE A Study of Interrelationships, 16th Edition Chapter 4 Interrelated Scientific Principles: Matter, Energy, and Environment Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. ® Chemistry is a branch of science that is concerned with matter , properties of atoms , compounds , and reactions between different substances. W h a t is Chemistry ? 4.4 The Structure of Matter Matter is anything that has mass and takes up space. The kinetic molecular theory describes the structure and activity of matter. It states that all matter is made up of one or more kinds of smaller sub-units (atoms) that are in constant motion. © McGraw Hill 20 Atomic Structure 1 The atom is the fundamental unit of matter. There are 92 types of atoms found in nature, with each being composed of: Protons (Positively charged). Neutrons (Neutral). Electrons (Negatively charged). Each kind of atom forms a specific type of matter known as an element. © McGraw Hill 21 © McGraw Hill 22 Interesting Facts About At om s Currently, scientists have discovered over 100 different types of atoms, of which 92 of them are present naturally, while the rest is made in labs. One of the first atoms, which was human-made is known as "technetium". We have seven billion billion billion atoms in our body, however, almost 98% gets replaced every year. The size of an average atom is about one-tenth of a billionth of a meter across. We all considered atoms to be the smallest unit of an element, in fact, they consist of even smaller particles known as quarks and leptons. An electron is a lepton. Proton and neutron are composed of three quarks each. https://www.thoughtco.com/interesting-facts-about-atoms-603817 The periodic table © McGraw Hill 24 H ow to read the periodic table ? Each row is called a period, All the elements in the same period have equal orbitals. The first row has 1 orbital to 7 orbitals in the bottom row. Each column is called a group All elements in the same group tend to react the same with other elements They have the same outer shell electrons know as the valence electrons https:// www.expii.com/t/how-to-read-the-periodic-table-overview-components-860 6 © McGraw Hill 25 What are the most common elements in our environment? One of the most common elements that make up our natural environment are: Hydroge n Oxygen Carbon Nitrogen © McGraw Hill 26 Atomic Structure 2 All atoms of the same element have the same number of protons and electrons, but may vary in the number of neutrons. Isotopes are atoms of the same element that differ from one another in the number of neutrons they contain. Access the text alternative for slide images. © McGraw Hill 27 The Nuclide Symbol Copyright © McGraw-Hill Education. Permission required for reproduction or display. The Molecular Nature of Matter 1 Molecules are atoms bonded together into stable units. Ions are electrically charged particles. Atoms that lose electrons = positively charged. Atoms that gain electrons = negatively charged. Compounds are formed when two or more atoms or ions bind to one another. Water (H2O). Table sugar (C6H12O6). © McGraw Hill 29 Important Compounds ( Can you guess their molecular formu Sugar/Glucose Methane Carbon dioxide Carbon monoxide Diatomic Oxygen Ozone Diatomic Hydrogen Water Sodium Chloride Diatomic Nitrogen Nitric oxide Nitrogen oxides Nitrous oxide Nitrogen dioxide Hydrocarbons Sulfur Dioxide Sulfuric Acid Acetic Acid Hydrochloric acid Sodium Hydroxide © McGraw Hill 30 A Word About Water 1 Water can exist in 3 phases: solid, liquid, and gas. ¾ of the Earth’s surface is covered with water. Water determines the weather and climate of a region, and the flow of water and ice shape the Earth’s surface. The most common molecule found in living things is water. Water molecules are polar with positive and negative ends. Unlike charges attract and water molecules tend to stick together. Much energy is needed to separate water molecules and convert liquid water to vapor. Thus, evaporation of water cools its surroundings. Water is the universal solvent. Most things dissolve to some degree in it. © McGraw Hill 31 Relationships Between the Kinds of Subunits Found in Matter Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Table 4.1 Relationships Between the Kinds of Subunits Found in Matter Category of Matter Subunits Characteristics Subatomic particles Protons Positively charged Located in nucleus of the atom Neutrons Have no charge Located in nucleus of the atom Electrons Negatively charged Located outside the nucleus of the atom Elements Atoms Atoms of an element are composed of specific arrangements of protons, neutrons, and electrons. Atoms of different elements differ in the number of protons, neutrons, and electrons present. Compounds Molecules or ions Compounds are composed of two or more atoms or ions chemically bonded together. Different compounds contain specific atoms or ions in specific proportions. Mixtures Atoms, molecules, or ions The molecular particles in mixtures are not chemically bonded to each other. The number of each kind of molecular particle present is variable. © McGraw Hill 32 Acids, Bases, and pH An acid is any compound that releases hydrogen ions in a solution. A base is any compound that accepts hydrogen ions in a solution. The concentration of an acid or base solution is given by a number called its pH. The pH scale measures hydrogen ion concentration. The scale is inverse and logarithmic. 7 = neutral. 0-6 = acidic (fewer OH− than H+). 8-14 = basic (more OH− than H+). © McGraw Hill 33 pH Scale The pH scale measures the acidity or how basic a solution is, it differentiates between 3 categories: - Acids anything below 7 (releases hydrogen ions in a solution) - Bases anything above 7 (accepts hydrogen ions in solution) - Neutral Solutions pH of 7, solutions that have equal of H+ ions and OH- ions, eg: water © McGraw Hill 34 HCl © McGraw Hill  H+ + Cl- 35 Acids, Bases, and pH Acid HCl  H+ + Cl- Base NaOH  Na+ + OH- Acid-Base reaction HCl + NaOH  Na+ + Cl- + H2O © McGraw Hill 36 Chemical Reaction: Is the process by which a group of chemical compounds tend to react with each other, resulting in their transformation from one form to many others. Organic matter consists of molecules that contain carbon atoms that are usually bonded to form rings or chains. All living things contain molecules of organic compounds. Typically, chemical bonds in organic molecules contain a large amount of chemical energy that can be released when the bonds are broken. © McGraw Hill 37 Chemical Reactions 1 Chemical bonds are attractive forces between atoms resulting from the interaction of their electrons. When chemical bonds are formed or broken, a chemical reaction occurs. In exothermic reactions, chemical bonds in the new compounds contain less chemical energy than the previous compounds. In endothermic reactions, the newly formed chemical bonds contain more energy than the previous compounds. © McGraw Hill 38 Chemical Reactions 2 Activation energy is the initial input of energy required to start a reaction. A catalyst is a substance that alters the rate of reaction, without being consumed or altered itself in the process. Catalysts can reduce activation energy. A catalytic converter in an automobile brings about more complete burning of fuel, resulting in less air pollution. © McGraw Hill 39 A Chemical Reaction Access the text alternative for slide images. © McGraw Hill 40 The Importance of Chemical Reactions in Our Daily Lives Chemical reactions play a vital part in our livesGenerate since they allow us to: heat Digest our food Generate electricity Chemical Reactions in The Environment A Photosynthesis The process by which plants absorb CO2 from the environment and convert it into O2 © McGraw Hill B C Rus Decomposition iron + oxygen ---> rust. t The break down of reaction compounds and organisms through chemical reactions. 42 Chemical Reactions in Living Things 1 Living organisms contain enzymes that reduce the activation energy needed to start reactions. Photosynthesis is a process used by plants to convert inorganic material into organic material using light. Carbon dioxide + water (in the presence of sunlight) produces glucose + oxygen. 6CO2 + 6H2O  C6H12O6 + 6O2. © McGraw Hill 43 Chemical Reactions in Living Things 2 Respiration is the process that uses oxygen to break down large, organic molecules into smaller inorganic molecules (releases energy organisms can use). All organisms, including plants, must carry on some form of respiration, since all organisms need a source of energy to maintain life. Glucose + oxygen produces carbon dioxide + water + energy. C6H12O6 + 6O2  6C O2 + 6H2O + energy. © McGraw Hill 44 Different Environmental Factors can Change The Rates of Chemical Reactions © McGraw Hill Concentration Temperature Physical state The higher the concentration of reactants in the environment the faster the chemical reaction Higher temperatures lead chemical reactions to occur at a faster rate. With the alteration of physical states of elements and compounds by the environment, chemical reactions would also change. 45 Role of Chemistry in Environmental Protection Production of new techniques: Using waste gas to make fuel and beneficial chemicals Using renewable resources The use of Non-petroleum fuels to minimize pollution Biofuels: It can be obtained from Sugar canes,Corn, Straw, and Wood. © McGraw Hill 46 4.5 Energy Principles Energy is the ability to perform work. Work is done when an object is moved over a distance. Kinetic energy is the energy contained by moving objects. Potential energy is energy due to relative position. © McGraw Hill ©Corbis/SuperStock RF 47 Potential and Kinetic energy calculations GPE = weight x height A 37 N object is lifted to a height of 3 meters. What is the potential energy of this object? KE = (mass x velocity2)/2 =1/2 mv2 What is the kinetic energy of a 45 kg object moving at 13 m/sec? © McGraw Hill 48 States of Matter 1 The state of matter depends on the amount of energy present. The amount of kinetic energy contained in a molecule determines how rapidly it moves. Solids: Molecular particles have low energy and vibrate in place very close to one another. Liquids: More energy; molecules are farther apart from one another. Gases: Molecular particles move very rapidly and are very far apart. © McGraw Hill 49 States of Matter 2 Access the text alternative for slide images. © McGraw Hill 50 States of Matter 3 Sensible heat transfer occurs when heat energy flows from a warmer object to a cooler object. The temperature of cooler matter increases and the temperature of warmer matter decreases. Latent heat transfer occurs when heat energy is used to change the state of matter, but the temperature of matter does not change. © McGraw Hill 51 First and Second Laws of Thermodynamics Energy can be converted from one form to another, but the amount remains constant. 1st Law: Energy cannot be created or destroyed; it can only be changed from one form to another. 2nd Law: When converting energy from one form to another, some of the useful energy is lost. Entropy is the energy that cannot be used to do useful work. © McGraw Hill 52 Effects of Chemical reactions on The Environment Increase Greenhouse emissions Pollution - As a byproduct of the release of some hazardous gases resulting from chemical reactions. - Burning is a reaction that produces a great amount of pollutant gases such as in the process of burning coal and fuel burning. - The greenhouse effect occurs when the quantity of carbon dioxide in the atmosphere rises, resulting in an increase in air temperature. 4.6 Environmental Implications of Energy Flow 1 Heat produced during energy conversion is dissipated into the environment. Chemical reactions. Friction between moving objects. Orderly arrangements of matter tend to become disordered. The process of becoming disordered coincides with the constant flow of energy toward a dilute form of heat. This results in an increase in entropy. © McGraw Hill 54 4.6 Environmental Implications of Energy Flow 2 Some forms of energy are more useful than others. High quality: Can be used to perform useful work (electricity). Low quality: Cannot be used to perform useful work (heat in the ocean). Temperature differential between two objects means that heat will flow from the warmer object to the cooler object. The greater the temperature differential, the more useful work can be done. © McGraw Hill 55 4.6 Environmental Implications of Energy Flow 3 Low-quality energy still has significance in the world. The distribution of heat energy in the ocean moderates the temperature of coastal climates. It contributes to weather patterns and causes ocean currents that are important in many ways. We can sometimes figure new ways to convert low-quality energy to high-quality energy. Improvements in wind turbines and photovoltaic cells allow us to convert low-quality light and wind to electricity. © McGraw Hill 56 Biological Systems and Thermodynamics In accordance with the second law of thermodynamics, all organisms, including humans, are in the process of converting high-quality energy into low-quality energy. When chemical-bond energy in food is converted into the energy needed to move, grow, or respond, waste heat is produced. From an energy point of view, it is comparable to the process of combustion. © McGraw Hill 57 Pollution and Thermodynamics A consequence of energy conversion is pollution. Wearing of brakes used to stop cars. Emissions from power plants. If each person on Earth used less energy, there would be less waste heat and other forms of pollution that result from energy conversion. The amount of energy in the universe is limited, and only a small portion of that energy is high-quality. © McGraw Hill 58 Scientific Measurements © McGraw Hill 59 Convert each of the following measurements to a unit that replaces the power of ten by a prefix. a. 3.29 x 10-3 g b. 2.89 x 103 m c. 2.25 x 10 -6 s d. 6.2 x 10-9 m Use exponential notation to express each of the following: © McGraw Hill a. 2.1 g to kg b. 9.3 nm to m c. 6.3 ms to s d. 3.2 cm to m 60