Welcome to the World of Chemistry

CHEMISTRY INTRODUCTION 5/31/2016Dr Seemal Jelani Chem-1002

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. 5/31/20163Dr 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. 5/31/20164Dr Seemal Jelani Chem-100

Physical Chemistry is interested in theories and experiments that describe the behavior of substances. Biochemistry is the study of the chemistry of living organisms. 5/31/2016Dr Seemal Jelani Chem-1005

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. 5/31/20166Dr 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! 5/31/20167Dr Seemal Jelani Chem-100

Chemistry 5/31/20168Dr Seemal Jelani Chem-100

Matter Matter = any material substance with Mass & Volume 5/31/20169Dr Seemal Jelani Chem-100

Matter Solid Liquid Gas comes in 3 phases 5/31/201610Dr Seemal Jelani Chem-100

Solid Definite Shape Definite Volume 5/31/201611Dr Seemal Jelani Chem-100

Liquid Indefinite Shape – takes the shape of the container Definite Volume 5/31/201612Dr Seemal Jelani Chem-100

Gas Indefinite Shape – takes the shape of the container Indefinite Volume – can expand and be compressed 5/31/201613Dr Seemal Jelani Chem-100

Elements one of the 100+ pure substances that make up everything in the universe 5/31/201614Dr Seemal Jelani Chem-100

Examples of Elements H= Hydrogen C= Carbon O= Oxygen N= Nitrogen S= Sulfur Na= Sodium Ca= Calcium K= Potassium I= Iodine Cl= Chlorine P= Phosphorus 5/31/201615Dr Seemal Jelani Chem-100

Atom the smallest particle making up elements 5/31/201616Dr Seemal Jelani Chem-100

Sub-atomic Particles Protons p+ p+ - positive charge, in nucleus Electrons - e - negative charge, orbiting nucleus Neutrons n0 n0 – no charge, in nucleus 5/31/201617Dr Seemal Jelani Chem-100

Drawing an Atom of Carbon C Atomic Mass minus Atomic No = n0n0 Atomic No = p+ p+ and e-e- Carbon has 6 p + and 6 e - Carbon has 6 n 0 5/31/201618Dr Seemal Jelani Chem-100

Drawing an Atom of Carbon 6 p + 6 n 0 e-e- e-e- e-e- e-e- e-e- e-e- 5/31/201619Dr 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 5/31/201620Dr Seemal Jelani Chem-100

Compounds They can be made of 2 or more different atoms combined to form Molecules H + O H 2 O = H O H 5/31/201621Dr Seemal Jelani Chem-100

5/31/2016Dr Seemal Jelani Chem Chemical formula lists the number of different atoms in a single molecule Structural formula shows the arrangement of the atoms in a single molecule

Molecules Glucose Sugar C 6 H 12 O 6 Chemical formula C H OH CC C CC H H H H H H OH O O H H O OH Structural formula 5/31/201623Dr Seemal Jelani Chem-100

Compounds Inorganic Compounds or Organic Compounds Usually don’t contain Carbon Generally come from the earth Generally simple molecule s Always contain C & H and usually O, N, sometimes S & P Originate in organisms Generally complex molecules 5/31/201624Dr Seemal Jelani Chem-100

Examples of Inorganic Compounds H + O = H 2 O = Water H + Cl = HCl = Hydrochloric Acid C +O = CO 2 = Carbon Dioxide Na + Cl = NaCl = Common Table Salt 5/31/201625Dr 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 5/31/201626Dr Seemal Jelani Chem-100