Nature of light and electromagnetic spectrum: According to Newton’s corpuscular theory, light is propagated as a stream of particles, called corpuscles. This could justify the phenomenon of reflection and refraction of light but failed to explain the phenomenon of diffraction, interference etc. Clerk Maxwell suggested that light waves are associated …
أكمل القراءة »Bohr’s model of the atom
Bohr’s model of the atom Neil Bohr in 1913 observed that basic features of Rutherford’s atomic model namely presence of nucleus and revolving electrons were correct but that the electrons revolved round the nucleus in certain allowed circular orbits and that the electrons did not radiate and therefore its energy …
أكمل القراءة »Rutherford model of atom
Rutherford model of atom Rutherford observed that atom has all the positive charge concentrated in a very small central region called the nucleus and that nucleus is surrounded by negatively charged particles called electrons revolving in orbits. He proved that the force of attraction between electrons and nucleus was counter …
أكمل القراءة »Atoms
ATOMS Law of constant composition: This states that “A chemical compound (if pure) always contains the same elements combined together in the same proportion by mass regardless of bow the compound is prepared or from where it is obtained”. Law of conservation of mass: This is defined as “In every …
أكمل القراءة »جدول الذائبية Solubility Chart
جـدول الذائبـية Solubility Chart : من خلال جـدول الذائبـية يمكن التنبؤ ما إذا كان الملح أو المركب قابل للذوبان في الماء أم لا . جـدول الذائبيـة Solubility Chart بوسترات (لوحات) كيميائية بدقة عالية (أكثر من 25 لوحة) من تصميم الأستاذ أكرم أمير العلي تطبيقات كيميائية …
أكمل القراءة »المونوميرات و البوليميرات (لوحة قابلة للتنزيل)
المونوميرات و البولوميرات (لوحـة قابلة للتنزيل) بوسترات (لوحات) كيميائية بدقة عالية (أكثر من 25 لوحة) من تصميم الأستاذ أكرم أمير العلي تطبيقات كيميائية من تصميم الأستاذ أكرم امير العلي متوفر للجوالات التي تعمل بنظام أندرويد android على سوق جوجل بلاي google play 1 – تطبيق ملصقات الجدول الدوري …
أكمل القراءة »Flory temperature -theta temperature
Symbol θ. The unique temperature at which the attractions and repulsions of a polymer in a solution cancel each other. It is analogous to the Boyle temperature of a nonideal gas. A polymer solution at the Flory temperature is called a theta (θ) solution. At the Flory temperature the virial …
أكمل القراءة »fluorite structure
A type of ionic crystal structure in which the cations have an expanded face-centered cubic arrangement with the anions occupying both types of tetrahedral hole. The cations have a coordination number of 8 and the anions have a coordination number of 4. Examples of compounds with this structure are CaF2, …
أكمل القراءة »flunitrazepam
A benzodiazepine used medically in some countries as a powerful hypnotic, sedative, and muscle relaxant. It was marketed in the US under the trade name Rohypnol. Flunitrazepam has become notorious as a so-called ‘date rape’ drug. It is quickly eliminated from the body, difficult to detect, and causes amnesia, so …
أكمل القراءة »CPMG sequence – Carr-PurcellMeiboom-Gill sequence
A sequence of pulses used for spin-echo experiments in nuclear magnetic resonance (NMR) in which the initial pulse is 90° followed by a series of 180° pulses. A CPMG sequence is designed so that the spin echoes die away exponentially with time. Spin-spin relaxation occurs characterized by a time constant …
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