General Chemistry (HST 111) Introduction PDF - Mansoura National University

Faculty of Health Science Technology Mansoura National University General Chemistry (HST 111) Introduction Prepared by Second semester Dr. Selwan Mahmoud...

Faculty of Health Science Technology Mansoura National University General Chemistry (HST 111) Introduction Prepared by Second semester Dr. Selwan Mahmoud 2024/2025 Dr. Reham Waheed What is chemistry? ▪ The branch of science that deals with chemicals. ▪ Chemicals include all day-to-day things you touch, see, and smell. ▪ Chemicals are everywhere (except in the vacuum). What are chemicals composed of? ▪ Chemicals are composed of different substances (substance means chemical material of which an object is composed e.g. ice is composed of substance water, or chemical material water).  Despite the benefits of chemistry, we have to be careful in dealing with chemicals. Many chemicals are toxic, others are potential cancer producers. Therefore, chemicals must be handled with control. What Is Risk Benefit Balance  Types of chemistry Fundamentally, chemistry is the study of matter and change. The way that chemists study matter and change and the types of systems that are studied varies dramatically. Traditionally, chemistry has been divided into five main subdisciplines: Organic, Analytical, Physical, Inorganic, and Biochemistry.  Over the last several years, additional concentrations have begun to emerge, including Nuclear chemistry, Polymer chemistry, Biophysical chemistry, Bioinorganic chemistry, Environmental chemistry, … etc.  Organic chemistry Organic chemistry is the study of chemicals containing carbon. Carbon is one of the most abundant elements on Earth Carbon is capable of forming a tremendously vast number of chemicals (over twenty million so far). Most chemicals found in every living organism are based on carbon.  Inorganic chemistry Inorganic chemistry is the study of chemicals that do not, in general, contain carbon. Inorganic chemicals are commonly found in rocks and mineral. One current important area of inorganic chemistry deals with the design and properties of materials involved in energy and information technology.  Analytical chemistry Analytical chemistry is the study of the composition of matter. It focuses on separating, identifying, and quantifying chemicals in samples of matter. An analytical chemist may use complex instruments to analyze an unknown material, in order to determine its various components.  Physical chemistry It is the study of macroscopic properties, atomic properties, and phenomena in chemical systems. As examples, a physical chemist may study The rates of chemical reactions, The energy transfers that occur in reactions The physical structure of materials at the molecular level.  Biochemistry Biochemistry is the study of chemical processes that occur in living things. Research may cover basic cellular processes up to understanding disease states, so that better treatments can be developed.  Important terms ❑ An element is a pure substance made up of atoms with the same number of protons. ❑ Carbon (C), oxygen (O2), hydrogen (H2) are examples of elements. ❑ The periodic table is a tabular representation of the known elements.  Important terms ❑ A molecule consists of two or more chemical elements that are chemically bonded together. ❑ Water (H2O) is an example of chemical compounds. ❑ The ratio of the elements in a compound is always the same. ❑ For example, in water, the number of H atoms is always twice the number of O atoms.  Important terms A mixture consists of two or more substances (element or compound) mixed together without any chemical bond. Salad is a good example. A mixture can also be separated into its individual components by mechanical means. ❑ Homogenous mixture Consist of more than one pure substance with properties that do not vary within the sample Mineral water ❑ Heterogenous mixture Consist of more than one pure substance and more than one phase Blood, milk, smoke, and chicken soup