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Se afișează postări din aprilie, 2013

ATOMIC MODELS

ATOMIC MODELS
ATOMIC MODEL CONCEPT


By "atomic model" means a simplified representation of a schematic structure of the atom, aiming to explain its properties.
       The introduction of such a concept was imperative, because without a base could not reach intuitive understanding of atomic structure (ie the structure of matter that surrounds us), which as noted earlier in this paper, is the very foundation of scientific knowledge itself.



            The first atomic model was developed by JJ Thompson after he managed to emphasize the electron as a particle constituent atom prompting by drift experiments in electric and magnetic fields, the specific tasks.            Thompson's model suggestively called "raisin cake", since the atom was regarded as a compact sphere within which were randomly distributed electric charges both positive and negative electrical ones who ensure the neutral atom orcarei view.                  But as occur naturally, the idea that atoms exist…

MODELE ATOMICE

MODELE ATOMICE
CONCEPTUL DE MODEL ATOMIC
   Prin " model atomic " se intelege o reprezentare simplificata, schematica, a structurii atomului, avand drept scop explicarea proprietatilor acestuia.
Introducerea unui astfel de concept era imperios necesara, intrucat fara o baza intuitiva nu se putea ajunge la intelegerea structurii atomului ( deci a structurii materiei care ne inconjoara ) care, asa cum mentionam in lucrarile de mai devreme, constituie chiar fundamentul cunoasterii stintifice insasi. ELABORAREA PRIMELOR MODELE ATOMICE 
Primul model atomic a fost elaborat de J. J. Thompson, dupa ce acesta a reusit sa puna in evidenta electronul ca particula constituenta a atomului determinandu-i, prin experimente de deviatie in campuri electrice si magnetice, sarcina specifica.            Modelul lui Thompson s-a numit sugestiv " cozonac cu stafide ", intrucat atomul era privit ca o sfera compacta in interiorul caruia ar fi fost distribuite aleator atat sarcinile electrice p…

STUDY OF ORGANIC CHEMISTRY

HISTORY

            Annotated leather tanning workshops and brewing in ancient Egypt, about the use of mineral products, vegetable and animal since five thousand years ago recorded the first Chinese pharmacopoeia, and about the use of purple by the Phoenicians extracted from marine mollusks to dye cloth and fabrics, are landmarks in the evolution of the human species and some of the first information regarding concerns about organic chemistry.
      The end of the century - XVIII - century appeared the first classifications of substances from vegetable and animal were organic substances (by analogy with the fact that they are produced by living organisms) and the mineral were called inorganic minerals (no life).
     Organic chemistry the term was introduced in 1808 by J.J. Berzelius you associate with all substances that are produced by living organisms and have in turn a vital force. force theory would be disproved in 1828 by F. Wöhler, who won for the first time in the laboratory by s…

CONTINUED DEVELOPMENT OF THEORIES OF, MICROCOSMOS''

CONTINUED DEVELOPMENT OF THEORIES OF, MICROCOSMOS''

  Referring to the study of the structure of matter called a philosopher

"Compared to philosophy - is math, compared with mathematics is philosophy."

                Scientific theories are, indeed, on the border between concrete and abstract of mathematics cold - trying to fit in formulas and equations all that exists around us and even ourselves - and philosophy, sometimes devoid of realism, a Universe too complex to be explained and whose understanding, if it were possible, it would only disturb her existence, if not empty of meaning to it.
               It is true that in the universe there is lowest'' ', also just as there is no "greatest." Just do it persivitate the frontier as interesting operation "microcosm" as that of "macrocosm ".
              We will always be looking for the smallest particles in the structure of matter, as in the search for the most distant gal…

FROM CONCEPT OF ATOM

FROM CONCEPT OF ATOM
FIRST hypotheses about the structure of matter




      Since ancient times, the issue deeper knowledge of objects and natural phenomena.   At the dawn of scientific knowledge, the matter is considered to be a whole and continuously.   This idea was supported by Xenofanes and school to eleatica in fifth-century BC    A current averse to this view appeared in the next century, when Leukippos and then Democritus introduced the hypothesis of discontinuity of matter, which is understood as being composed of very small particles that can not be fragmented and the very reason they named atoms (atoms in Greek means something that can not be cut).      Then seek to identify elements that make up the substance to be brought proof discontinuity them.       The concept of Empedocles in the fifth century BCE as the constituents of matter as earth, water, air and fire was approved a century later Aristotle, who tried to argue because these "essential elements" correspond perfec…

ORIGINEA NOTIUNII DE ATOM

ORIGINEA NOTIUNII DE ATOM
PRIMELE IPOTEZE ASUPRA STRUCTURII MATERIEI


      Inca din antichitate s-a pus problema cunoasterii mai profunde a obiectelor si fenomenelor naturale.   In zorii cunoasterii stintifice, materia se considera a fi un tot unitar   si continuu.    Ideea aceasta a fost sustinuta de Xenofanes si de scoala sa eleatica, in secolul al -V- lea i.e.n.    Un curent potrivnic acestei conceptii a aparut in secolul urmator, cand Leukippos si apoi Demokritos au introdus ipoteza discontinuitatii materiei, aceasta fiind inteleasa ca fiind alcatuita din particule foarte mici, care nu mai pot fi fragmentate si care chiar din acest motiv au primit denumirea de atomi ( atomos in limba greaca inseamna ceva ce nu mai poate fi taiat ).      S-a cautat apoi identificarea unor elemente din care este alcatuita substanta, pentru a fi adusa dovada discontinuitatii ei.        Conceptia lui Empedocles in secolul V i.e.n. conform careia constituentii materiei ar fi pamantul, apa, aerul si focul a f…