نتكلم شوية عن كل جزء فيهم واهم النقط اللى لازم تكون ف دماغنا واحنا داخلين الامتحان يعنى مش كل النقط ع محدش يفهم غلط اولا :- طبيعة الضوء والطيف Light in chemistry :- is electromagnetic radiation that is visible to human eye Light in physics :- is electromagnetic radiation of any wavelength whether visible or not wavelength ( λ ) : the distance between two adjacent crests or troughs (( 1A = 10-8 cm )) frequency (ν ) : the number of waves which pass through a given point in one second (( 1 HZ = S-1 )) Amplitude ( A ) : the measure of the height of a wave or the depth of its trough velocity ( c ) : the distance traveled by a wave in one second wave number : is the number of wavelength per centimeter (( V= 1/λ )) electromagnetic spectrum : the arrangement of different types of electromagnetic radiations in order of increasing wavelengths or decreasing frequencies Dual nature of light : there are two ideas 1- wave nature of light 2- particle nature of light types of spectra ( absorption , Emission ) مهم Emission spectra can divided into three types : a) Continuous spectra : the spectra where no separation zones is observed . b) Line spectra : consist of parallel lines of definite frequencies . c) Band spectra : consist of bands of very adjacent lines . the emission spectrum of hydrogen can divided into five series : 1- Lyman series ( in UV region ) . 2- Balmar series ( in visible region ). 3- Paschen series ( in the border of IR ). 4- Brackett series ( in the side of IR ). 5- Pfund series ( in the IR ). the energy decrease from 1 to 5 the wavelength of any line can be determine by Rydberg equation 1/( λ)=RH ( □(1/(n_1^(2 ) ) - 1/(n_2^2 ) )) مهم Dalton’s atomic theory(the first truly theory of the atomic structure ) Bohr’s theory ( Explanation of hydrogen spectrum ) الجزء ده مهم وبيجى ف صورة اكمل لاى حاجه نبهت عنها او عرف او قارن مثلا بين انواع الطيف او انواع طيف الانبعاث او اكتب نبذه #catalyst #MB
Posted on: Thu, 08 Jan 2015 17:29:04 +0000