CHEM-FOR-ENG.docx

**THE NATURE OF SCIENCE** - **Chemistry** has been called the "central science" because it is important to so many other fields of scientific study. - **Chemistry** is the branch of science concerned with the properties, composition, and structure of substances and the changes they...

**THE NATURE OF SCIENCE** - **Chemistry** has been called the "central science" because it is important to so many other fields of scientific study. - **Chemistry** is the branch of science concerned with the properties, composition, and structure of substances and the changes they undergo when they combine or react under specified conditions. **IMPORTANCE OF CHEMISTRY IN OUR DAILY LIVES:** 1. It provides men the **basic necessities** in life like *shelter*, *food* and *clothing*. 2. It provides men **luxuries in life** like *convenient* *transportation*, *advance* and *fast* means of *communication*, use of *computers*, use of *cosmetics*, *perfumes*, *etc*. 3. Researchers in chemistry help **improve the synthesis of chemicals** needed to **combat disease** such as *antibiotics*, *anesthetics*, *antiseptics*, *hormones* and *others*. 4. It explains the **composition of major classes of foods** and their **nutritional values** 5. It helps in the **advancement of scientific and technological studies** like *telecommunication* *systems* and *computer* *studies*. 6. It **enhances the awareness** on how the *body works* and on the **chemical changes** that occur within the *body system*. 7. It leads to the **discovery of organophosphorus pesticides** which along with other pesticides *reduce crop losses*. **BRANCHES OF CHEMISTRY** 1. **Inorganic Chemistry** - the study of [all the elements and their compounds] with the *exception of carbon* *and its compounds* investigates the characteristics of substances that are *not organic*, such as *nonliving matter* and *minerals* found in the earth\'s crust. 2. **Organic Chemistry** - Branch of chemistry dealing with [compounds of carbon.] 3. **Analytical Chemistry** - This kind of chemistry deals mostly with the [composition of substances.] Collection of techniques that allows exact laboratory examination of a given sample of material. - Chemists perform [qualitative analysis] or substances in a sample & [quantitative analysis] for the amount of each substance. **Qualitative Chemistry** - the *atoms and molecules present* are identified, with particular attention to trace elements. **Quantitative Chemistry** - the *exact weight* of each constituent is obtained as well. 4. **Biochemistry** - encompasses the study of the [chemical nature of living material] and of the [chemical transformations] that occur within it. A science that is concerned with the [composition and changes in the formation of living species.] This type of chemistry utilizes the concepts of [organic and physical chemistry] to make the world of living organisms seem much clearer. 5. **Physical Chemistry** - is concerned with the [physical properties of materials], such as their *electrical and magnetic behavior and their interaction with electromagnetic fields.* This chemistry is defined as dealing with the [relations between the physical properties of substances and their chemical formations along with their changes.] **SCIENTIFIC METHOD (based on the module)** 1. Purpose/Question 2. Research 3. Hypothesis 4. Experiment 5. Data/Analysis 6. Conclusion **SCIENTIFIC METHOD (based on the discussion)** 1. Observation 2. Hypothesis/Model 3. Experiment 4. Analyze Data 5. Conclusion **ALUMINUM** - In the *19^th^ century*, aluminum is [rare and precious metal] - Pure aluminum *never* occurs in nature - [Found in Bauxite], an ore - Its common use is the [collaboration between chemistry and engineer] **THE HISTORY OF CHEMISTRY** **Timeline of Development** **I. Prehistoric Era** The history of chemistry started when people stated to use of [fire, cook food and baked pottery, production of wine and use of cosmetics ] **II. Greek Civilization** - **Thales** assumed that [all matter was derived from water ] - **Democritus** said the [ATOM is the simplest unit of matter] - **Empedocles** said that all matter was composed of *four elements*: [fire], [air], [water], and [earth]. - **Aristotle** described the *four qualities* were found in nature: [heat], [cold], [moisture], and [dryness]. **III. Beginning of Christian Era - End of 17^th^ Century (Alchemy *"al chemia")*** - Alchemists attempted to transmute [cheap metals to gold]. This is the precursor of Chemistry. - **Paracelsus** -- *Auroleus Phillipus Theostratus Bombastus von Hohenheim*. Searched for [medicine to cure sickness]. He was credited with the introduction of opium and mercury into the arsenal of medicine. His works also indicate an [advanced knowledge of the science] and [principles of magnetism]. The precursor of chemical pharmacology and therapeutics and the [most original medical thinker of the sixteenth century]. - **Galileo** -- introduced [accurate measurements] - **Robert Boyle** - *disproved* Aristotle's four elements theory ["Skeptical Chemist"]. He conceptualized the [Boyle's Law]. **IV. End of 17^th^ Century-Mid 19^th^ Century (Traditional Chemistry)** - **George Ernst Stahl** -- [Phlogiston theory] - **Joseph Priestley** - [Isolated oxygen] by heating mercuric oxide - **Jan Baptista van Helmont** - kinds of air-like materials "gas" [Carbon Dioxide] - **Antoine Lavoisier** - He *disproved* the *phlogiston theory*. He is the [Father of modern chemistry]. - **Mikhail Vasilyevich Lomonosov** - Lomonosov [rejected the phlogiston theory], and anticipated the [kinetic theory of gases]. Lomonosov was the *first person to record the freezing of mercury*, and to *hypothesize the existence of an atmosphere on Venus*. He demonstrated the [organic origin] of [soil], [peat], [coal], [petroleum], and [amber]. In he published a catalogue of over *3,000 minerals*, and in he explained the *formation of icebergs*. - **John Dalton** - developed the [Atomic Theory] - **Rudjer Joseph Boscovich** - developed the [modern atomic theory] - **Heinrich Geissler** -- developed the [first vacuum tube] - **William Crookes** -- discovered the [cathode rays] - **Eugene Goldstein** - discovered proton - **Michael Faraday** - Invented the [electric motor] - **Wilhelm Conrad Röntgen** -- discovered [x-rays] - **Henri Becquerel** -- discovered [spontaneous radioactivity] - **Joseph John Thomson** -- discovered the [electron and its properties] - **Robert Andrews Millikan** -- determined the [mass of an electron] - **James Chadwick** -- discovered the [neutron] - **Ernest Rutherford** -- determined the [three types of radioactivity] - **Marie and Pierre Curie** -- determined the [radioactive properties] emitted by [uranium], [thorium], [radium] & [polonium] - **Niels Bohr** - Proposed that [electrons could only reside in certain energy levels or quanta] - **Enrico Fermi** - [neutron bombardment] & [nuclear fission] - **Dmitri Ivanovich Mendeleev** -- developed the [Periodic Law] and the [properties of the chemical elements.] The [Father of the Periodic Table.] - **Henry Moseley** - Determined the [atomic numbers] of all the known elements. [Arranged the periodic table] according to increasing atomic numbers.