Lecture: Introduction to Chemistry 1Preview The lectures in this unit cover an introduction to chemistry and matter, working with numbers and units, and an introduction to atoms and the periodic table. This lecture covers the nature of chemistry and scientific learning. Introduction to Chemistry The first question we have to ask ourselves is why study chemistry at all? Aside from the fact that some programs require it and therefore we don’t have a choice, there must be some compelling reason that chemistry is considered important enough to inflict upon our studious population (or to bless them with, depending on your perspective). The short answer to this question is that chemistry is central to all other sciences: by it we understand them. The following is a short list of the many sciences and other subject areas that chemistry plays a significant part in. Maybe you can think of some more! Biology Physiology Medicine Pharmacy Exercise Science Nutrition Foods Physics Engineering Astronomy Geology Materials Science Construction Art Restoration Music Currency Technology Film Electrics In this class we focus on the contributions that chemistry makes to the health sciences: including biology, physiology, medicine, nutrition, exercise science, and pharmacy. It is my hope that you view this not as a ‘chemistry’ class but as your first ‘nursing’ class or your introduction to the fundamentals of medicine and medicinal interactions. The second question we have to ask ourselves is what is chemistry? The short is that chemistry is the study of matter: anything that has mass and occupies space. Once we realize that it’s clear why chemistry is so central; there are very few subjects we study that do not deal with matter. So that brings us to a third question or concern: in this class we’ll talk a LOT about the fundamental nature of matter at the smallest level possible – the atom. This is an indivisible unit of any element, of which there are ~ 100 known and from which all matter in the universe is composed. This unit is far too small to be seen or measured with tools we have currently available. So the question is: How do we know what we’re talking about? How do we know that what we teach you is really true even though we can’t see it? This is a valid question and I want to answer it in two parts: in this lecture we will take a close look at the scientific method. In the next lecture we will talk about making observations on the macroscale which help us understand the microscale. The Scientific Method is the process by which scientists or researchers attempt to discover truth. Depending on the textbook you see it in there may be more or fewer steps but they are all generally the same. You are likely familiar with most of the steps listed:Lecture: Introduction to Chemistry 2 SCIENTIFIC METHOD 1 – State the problem (or initial observation) 2 – Collect Data (make additional observations) Qualitative observations – involves describing a quality (color, state of matter) Quantitative observations – involves measuring a quantity (mass, temperature) 3 – Make a Hypothesis (tentative explanation: needs to be tested) 4 – Design and administer an Experiment specifically to test the Hypothesis in a different environment (if possible!) 5 – Repeat. If the experiments repeatedly agree with our hypothesis then we have a theory to explain the problem. Theories can become stronger as they are repeated and confirmed in many experiments in many settings by many researchers and as applications are developed based on the principles. However, a theory is a human interpretation of events as we see it and is not necessarily a description of natural law. Theories differ from scientific laws in that laws attempt to describe natural phenomena whereas theories attempt to explain natural phenomena. For instance, the Law of Conservation of Energy states that the total energy of an isolated system remains constant – it is conserved over time. This law describes what happens to energy. The Atomic Theory states that matter behaves the way it does because it is composed of discrete units called atoms – it is explaining the fundamental nature of matter. It would be disingenuous to compare a well-established theory to a hypothesis; it would be silly to say “well the atomic theory is only a theory” as though that meant it was a very tentative and poorly-supported model. But the Scientific Method as listed above is not a complete picture of science today. Today, after a Researcher has applied the method to come to knowledge of truth not previously known, she tries to publish it in a Scientific Journal. These regularly-published magazines accept submissions from the scientific community and before publishing the submissions they are read and accepted (or rejected) by peer reviewers: usually scientists who have intimate knowledge about the subject being discussed. Once the paper is published the scientific community at large has access to it and may test the initial researcher’s observations and attempt to apply them to their own work. As the work of these secondary researchers is completed and their papers are published, the community at large accepts, modifies, or rejects the researcher’s initial claims. Over time the knowledge gained from these interactions elevates the working level of knowledge that the entire community has. This may be considered part of step 5 of the scientific method – REPEAT. Publishing and referencing published work in this process is step 5 on steroids as many individuals ‘repeat’ the work and confirm it in their own ways. Research is a process by which one group carefully studies one or more individual facets of a problem. True understanding of a phenomenon or field includes continuous study of the aggregate of research available in that field or on that phenomenon. Over time and with enough researchers working on a problem we hope to come to a consensus about what is true and what isLecture: Introduction to Chemistry 3not. This is based on data and observations repeated by many people and validated by useful application of findings. In this sense, we know that what we are teaching is true because it has been tried and tested in this manner countless times. The scientific method is a marvelous thing by which we come closer to an understanding of Truth. But that