Welcome to the World of Chemistry

CHEMISTRY INTRODUCTION 9/12/2018 Dr Seemal Jelani Chem-100

What is Chemistry? Chemistry is the study of the composition of matter and the changes matter undergoes. Matter is anything that takes up space and has mass. Chemistry can be very practical and have obvious applications in everyday life. Chemistry can also be very theoretical (without daily application). But what is theoretical today may be practical tomorrow. 9/12/2018 Dr Seemal Jelani Chem-100

The Branches of Chemistry (Areas of Study) Organic Chemistry is the study of all substances containing the element carbon. Inorganic Chemistry specializes in substances that don’t contain carbon. Analytical Chemistry is concerned with the composition of substances. 9/12/2018 Dr Seemal Jelani Chem-100

Biochemistry is the study of the chemistry of living organisms Physical Chemistry is interested in theories and experiments that describe the behavior of substances. Biochemistry is the study of the chemistry of living organisms Environmental Chemistry is the study of the chemistry of environment Green Chemistry is the study of saving the environment 9/12/2018 Dr Seemal Jelani Chem-100

Why Study Chemistry? You and everything around you involve chemistry. You are made from chemicals and you use chemicals everyday-when you breathe, drink a glass of water, wash your hair, eat a snack… Humans have a natural desire to understand how things work Chemistry is one branch of knowledge that grew from human curiosity. Knowledge of basic chemistry can help you make informed decisions. 9/12/2018 Dr Seemal Jelani Chem-100

Applied Chemistry vs. Pure Chemistry Applied chemistry is used to attain a specific goal such as formulate a new paint. Pure chemistry accumulates knowledge for its own sake. This year, you will recognize many ways in which chemistry affects your life. And maybe you’ll consider a career in chemistry! 9/12/2018 Dr Seemal Jelani Chem-100

Chemistry 9/12/2018 Dr Seemal Jelani Chem-100

Matter Matter = any material substance with Mass & Volume 9/12/2018 Dr Seemal Jelani Chem-100

Matter comes in 3 phases Solid Gas Liquid 9/12/2018 Dr Seemal Jelani Chem-100

Solid Definite Shape Definite Volume 9/12/2018 Dr Seemal Jelani Chem-100

Liquid Indefinite Shape – takes the shape of the container Definite Volume 9/12/2018 Dr Seemal Jelani Chem-100

Gas Indefinite Shape – takes the shape of the container Indefinite Volume – can expand and be compressed 9/12/2018 Dr Seemal Jelani Chem-100

Elements one of the 100+ pure substances that make up everything in the universe 9/12/2018 Dr Seemal Jelani Chem-100

Examples of Elements Na = Sodium Ca = Calcium C = Carbon O = Oxygen K = Potassium Kalium H = Hydrogen I = Iodine N = Nitrogen Cl = Chlorine S = Sulfur P = Phosphorus 9/12/2018 Dr Seemal Jelani Chem-100

Atom the smallest particle making up elements 9/12/2018 Dr Seemal Jelani Chem-100

Sub-atomic Particles Protons p+ - positive charge, in nucleus Neutrons n0 – no charge, in nucleus Electrons - e- negative charge, orbiting nucleus 9/12/2018 Dr Seemal Jelani Chem-100

Drawing an Atom of Carbon 12.011 6 Atomic No = p+ and e- Carbon has 6 p+ and 6 e- Atomic Mass minus Atomic No = n0 Carbon has 6 n0 9/12/2018 Dr Seemal Jelani Chem-100

Drawing an Atom of Carbon e- e- 6 p+ 6 n0 9/12/2018 Dr Seemal Jelani Chem-100

Compounds 2 or more elements chemically combined to form a new substance with new properties What is meant by Properties The way a chemical substance looks and behaves 9/12/2018 Dr Seemal Jelani Chem-100

Compounds They can be made of 2 or more different atoms combined to form Molecules H O 2H + O H2O = 9/12/2018 Dr Seemal Jelani Chem-100

lists the number of different atoms in a single molecule Chemical formula lists the number of different atoms in a single molecule Structural formula shows the arrangement of the atoms in a single molecule 9/12/2018 Dr Seemal Jelani Chem-100

Molecules Glucose Sugar C6H12O6 Chemical formula Structural formula C 9/12/2018 Dr Seemal Jelani Chem-100

Compounds or Generally come from the earth Generally simple molecules Inorganic Compounds or Organic Compounds Always contain C & H and usually O, N, sometimes S & P Originate in organisms Generally complex molecules Usually don’t contain Carbon Generally come from the earth Generally simple molecules 9/12/2018 Dr Seemal Jelani Chem-100

Examples of Inorganic Compounds H + O = H2O = Water H + Cl = HCl = Hydrochloric Acid C +O = CO2 = Carbon Dioxide Na + Cl = NaCl = Common Table Salt 9/12/2018 Dr Seemal Jelani Chem-100

Examples of Organic Compounds C, H + O Carbohydrates = Sugars, starches & cellulose C, H + O Lipids = Fats & Oils C, H, O, N, & sometimes P + S Proteins C, H, O, N, + P Nucleic Acids – DNA & RNA 9/12/2018 Dr Seemal Jelani Chem-100