ChemistryChemistryIntroductionIntroduction
Dr. Mohamed Abd-Elhakeem
College of Biotechnology
General Chemistry
Lecture 1
• What is the chemistry?• What happened if the atomic structure collapse?• Why water don’t burn?• How we can calculate the calories of food?• What is the mechanism of air condition?• What are the information that can be obtained from
the periodic table?• What is the mean of color and how it is formed?• How can we determine the constituents in your juice?• How the atoms bind to each other to form compounds?• Why water able to dissolve salt and not able to solve
oil?• Do you hear about bio battery?• Do you know about the revolution of nanotechnology?
ChemistryChemistry• Chemistry = the study of matter and the
transformation it undergoes EVERYTHING is a CHEMICAL
o Table salt = sodium chloride, NaClo Table sugar = sucrose, C12H22O11
o Clothes: Wool? Cotton? Polyester?o Body: lipids, Proteins, Carbohydrates,
DNA/RNAo You name it– it’s a chemical!
Chemistry as the Chemistry as the “Central Science“Central Science””
Macroscopic, Microscopic & Particulate Macroscopic, Microscopic & Particulate
MatterMatter
• Matter: “ Anything that has mass and takes up space (occupies volume)“
Classification of Classification of MatterMatter
4 Physical States: solid, liquid, gas, plasma
Solid:Fixed shape and fixed volume; Atoms tightly packed together
Classification of Classification of MatterMatter
Liquid:No fixed shape but maintains a fixed volume Atoms loosely packed together, slide around
each other
Classification of Classification of MatterMatter
Gas:No fixed shape or volumeAtoms not really associated with
neighbors at all
Classification of Classification of MatterMatter
Plasma:mix of subatomic particles with not organization (sun)
Microscopic view of a gas.
Microscopic view of a liquid.
Microscopic view of a solid.
Properties of MatterProperties of MatterPhysical Properties =
characteristics of a material
Color MassTemperatureOdorDensityHardnessSolubilityConductivity (heat or
electrical)Freezing/boiling point
Chemical Properties = describe how a material reacts with another type of matter
Ability to burnAbility to rust / corrodeAbility to make a
solution acidic or basicLack of ability to react
with something
Changes in Matter - Changes in Matter - Physical & Physical &
ChemicalChemical
• Physical Change: “ A change that alters the physical form of matter without changing its chemical identity “
• Chemical Change: “ A change which changes the chemical identity of the substance and creates one or more new substances “
Changes in Matter - Changes in Matter - Physical ChangePhysical Change
A Melting Ice Sickle
Solid Water
Liquid Water
•Example of a Physical Change:
Changes in Matter - Changes in Matter - Chemical ChangeChemical Change
•Example of a Chemical Change: The Electrolysis of Water (H2O)
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Hydrogen Gas
Oxygen Gas
Negative Electrode Positive Electrode
ParticulateViewpoint
The Chemical Identity of Water ( H2O ) is changed
into the elements Hydrogen ( H2 ) and Oxygen ( O2 )
2H2O 2H2 + O2
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Classification of Matter
Matter - Anything that occupies space and has
mass (solid, liquid or gas)
Heterogeneous Mixture: Non-uniform composition
Homogeneous Matter: Uniform composition
Pure Substances: Fixed composition; cannot be
further purified
Physically Separable Into
Solution: Homogeneous
mixturePhysically Separable Into
Compounds: Elements united in
fixed ratios
Elements: Cannot be subdivided by
chemical or physical changes
Chemically decomposable Into
Combine Chemically to
Elements - The Most Simple Kind of Matter
Pure Substance: Matter that cannot be separated into two or more types of matter by physical means is called pure matter. Pure matter consists of two types, elements and compounds.
Element: Elements are substances that cannot be separated into two or more types of matter by physical or chemical methods.
Chemical Compounds - Atoms in Combination
Chemical Compounds: “Compounds are composed of two or more elements chemically combined in definite ratio”
OrAny pure substance that can be decomposed by a chemical change into two or more pure substances
Examples: H2O Water
NaCl Sodium Chloride
C2H6O Ethanol
C6H12O6 Sugar
MixturesMixtures
• Mixture is the type of substance that can be physically separated into more than one component. It may be homogeneous or heterogeneous.
• o A homogeneous mixture: (called also A solution), is a
mixture that has the same composition and properties throughout.
o A heterogeneous mixture: varies in composition and/or properties from one part of the mixture to another as in a glass of ice water
Sugar dissolved in water
Gold blended with silver (18 karat gold)
The air we breathe - a mixture of oxygen and nitrogen
Solutions: “Homogeneous mixtures, either liquid, solid or gaseous”
Homogeneous mixture
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Table salt is stirred into water (left), forming a homogeneous mixture called a solution (right)
Heterogeneous Sample:
•A mixture of cooking oil and water (two phases develop
•Concrete (sand, rock, cement, etc)
•A mixture of sand, sawdust, iron fillings and water
Sand and water do not mix to form a uniform mixture
Mixtures and Pure Substances (cont)
continue…..
Classification of Classification of MatterMatter
Chemistry branchesChemistry branches• Chemistry is typically divided into several major sub-
disciplines. There are also several main cross-disciplinary and more specialized fields of chemistry.
• Analytical chemistry is the analysis of material samples to gain an understanding of their chemical composition and structure.
• Biochemistry is the study of the chemicals, chemical reactions and chemical interactions that take place in living organisms. Biochemistry and organic chemistry are closely related, as in medicinal chemistry or neurochemistry. Biochemistry is also associated with molecular biology and genetics.
• Inorganic chemistry is the study of the properties and reactions of inorganic compounds.
• Nuclear chemistry is the study of how subatomic particles come together and make nuclei.
• Organic chemistry is the study of the structure, properties, composition, mechanisms, reactions and synthesis of organic compounds. An organic compound is defined as any compound based on a carbon skeleton.
• Physical chemistry is the study of the physical and fundamental basis of chemical systems and processes. In particular, the energetics and dynamics of such systems and processes are of interest to physical chemists.
• Quantum chemistry providing a mathematical description of the dual particle-like and wave-like behavior and interaction of matter and energy
Chemical symbolChemical symbol• chemical element is identified by an internationally
used symbol consisting of one or two letters.
• The first letter of an element’s symbol is always capitalized. If the symbol has a second letter, it is a lowercase (small) letter.
• The symbol is an abbreviation of the element’s name, but some symbols represent names in languages other than English.
SymbolsSymbols• All elements have
their own unique symbol.
• It can consist of a single capital letter, or a capital letter and one or two lower case letters.
C Carbon
CuCopper
• What is the difference between
CO and Co
• Chemical formula shows the kind and proportion of atoms of each element that occurs in a particular compound
Symbol Name Symbol NameSbAuFePbHgKAgNaSnWPZnHeNeAr
Antimony Gold Iron Lead Mercury Potassium Silver Sodium Tin TungstenPhosphorus ZinkHeliumNeonArgon
HOCCaMgMnCuClBrIFS
HydrogenOxygen CarbonCalcium MagesiumManganeseCupper Chlorine Bromine IodineFlourine Sulpher