Simplified Chemistry

 

Hund’s rule of maximum multiplicity

It states that no electron pairing takes place in the p, d and f orbitals until all the orbitals of the given sub-shell contain 1 electron each with parallel spins.

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Aufbau principle

Aufbau principle: According to this principle, the electrons enter the various orbitals in the order of increasing energy. This means that electrons occupy the lowest orbital first and then the orbitals of next higher energy and so on. The different orbitals are filled up in the following order as given below.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f,…

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Quantum numbers

Quantum numbers: These are numbers which are used to specify the location and energy of an electron and size, shape and orientation of the orbital to which a particular electron belongs.

Principal or total quantum number (n): This quantum number is identical with that used in Bohr Sommer field theory. It can have only non zero positive integral values.

i.e. n= 1, 2, 3, 4 ……….ꝏ

It quantizes…

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Nature of light and electromagnetic spectrum

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 with both electric and magnetic fields, i.e. light may be described as  electromagnetic waves or radiations. there are…

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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 remained constant. However, the electron could jump from outer stationary orbit to inner orbit and while…

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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 balanced by the centrifugal force acting on the revolving electron. This provided stability to the atom.

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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 chemical reaction, the total mass of the products is the…

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NATURE AND SCOPE OF CHEMISTRY

NATURE AND SCOPE OF CHEMISTRY

Chemistry. It is the branch of science which deals with the composition, preparation and properties of the substances.

Main branches of chemistry: (1) Inorganic chemistry (2) Physical chemistry (3) Organic chemistry (4) Biochemistry (5) Analytical chemistry (6) Agricultural chemistry (7) Industrial chemistry.

Scientific Methods : The scientific method consist of the following five steps :

1 -…

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الأنظمة البلورية crystal systems

الأنظمة البلورية: تعرف البلورة بأنها جسم صلب متجانس يحده من الخارج أسطح ملساء مستوية تعرف باألوجه البلورية، التي تعكس الترتيب الذري الداخلي المميز للمادة المتبلورة . تتحكم الظروف السائدة أثناء تكوين البلورات كالضغط، والحرارة، و البيئة الكيميائية، في حجم وطبيعة األوجه البلورية المتكونة. وتعرف الأسطح المستوية التي تحد البلورة من الخارج بالأوجه البلورية crystal faces ، وإذا وجدت الأوجه البلورية كلها أو بعضها فإنها تساعد كثيرا في التعرف على المعادن حيث إنها…

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جدول الذائبية Solubility Chart

جدول الذائبية Solubility Chart

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