Cement                                                 oxide (Na2O) 0.1-0.5%, Sulphur Trioxide
                                                       (SO3) 1-2%
   A cement is a binder, a substance that sets
    and hardens and can bind other materials           Portland cement consists essentially of
    together.                                          compounds of lime (calcium oxide, CaO)
   Concrete = Cement + water + sand +                 mixed with silica (silicon dioxide, SiO2) and
    gravel                                             alumina (aluminum oxide, Al2O3). The lime is
   Plaster = Cement + water + sand                    obtained from a calcareous (lime-containing)
   Mortar = Cement + lime + sand                      raw material, and the other oxides are derived
                                                       from an argillaceous (clayey) material.
Composition of cement
Lime (CaO) 60-65%, Sillica (SiO2) 20-25%,
Alumina (Al2O3) 4-8%, Iron Oxide (Fe2O3) 2-            It is the chemical substances used for
4%, Magnesium Oxide (MgO) 1-3%, Sodium                 diagnosis, treatment, and prevention of disease
                                          Classes of Medicine
     Class                    Cure/treatment/prevent      Medicine(s)
     Antipyretics             fever                       aspirin, paracetamol, analgin, novalgin,
     (pyrexia/pyresis)                                    phenacetain, etc.
     Analgesics               pain                        aspirin, paracetamol, morphine, etc.
     Antimalarial drugs       Malaria                     chloroquin
     Antibiotics              inhibiting germ growth      penicillin,      ampicillin,  amoxicillin,
                                                          tetracycline, etc.
     Antiseptics              Prevent germ growth near    Dettol, Savlon, Boric acid, hydrogen
                              burns, cuts and wounds      peroxide, etc.
     Mood stabilizers         moderate the manic highs    lithium, valpromide, etc.
                              and bipolar disorder
     Hormone replacements     -                           Premarin, Angeliq, etc.
     Oral contraceptives      -
     Stimulants               -                           methylphenidate (Ritalin)
     Tranquilizers            -                           meprobamate, chlorpromazine, reserpine,
                                                          chlordiazepoxide, diazepam, etc.
     Statins                  -                           lovastatin, pravastatin, and simvastatin,
Polymers                                               Plastic
These are substances whose molecules have                 It is a synthetic material made from a wide
high molar masses and are composed of a                    range of organic polymers such as
large number of repeating units. There are                 polyethylene, PVC, nylon, etc. Types of
both naturally occurring and synthetic                     Plastic : Thermoplastics and Thermosets
polymers.       Among    naturally occurring              Thermoplastics which are softened by
polymers are proteins, starches, cellulose, and            heat and can be moulded. (Injection
latex.                                                     moulded, blow moulded or vacuum
                                                           formed). e.g. acrylic, polypropylene,
                                                           polystyrene, polythene and PVC.