Each atom is made up of an inner core called the nucleus.  – Most of the atom’s mass is located in the relatively small nucleus.  – The rest of the atom is comprised of a relatively large region outside the nucleus where the electrons are found. – The atom is made of 3 subatomic particles: Positively charged protons Neutral particles …

Dalton’s Model of the atom. It is the basis of our understanding of the nature of matter. The following four statements comprise Dalton’s Model: a –  All matter is made up of extremely tiny. particles. called atoms. b-  Atoms are indivisible. c – Atoms of the same element are alike. d –  Atoms of different elements are different. e – …

The law of Conservation of Mass states that the mass of matter before and after a chemical change remains the same. The number of atoms also remains the same. The only thing that changes is the arrangement of the atoms. For example, the mass of hydrogen and oxygen before they combine to make water is the same as the mass …

Like matter, energy can be classified in different ways. For example, energy can either be kinetic or potential. Kinetic energy is energy of motion. Gases are made of molecules that have more kinetic energy than molecules in the solid phase of that substance. For example, water molecules in steam have greater kinetic energy than molecules in liquid water. Potential energy …

Substances can undergo three type of changes: – Physical changes – Chemical changes (also known as chemical reactions) – Nuclear changes (also known as nuclear reactions) In a physical change the appearance (color, shape, etc.) of the substance may change, but the substance will remain the same substance. A phase change is an example of a physical change. For example, …

Matter is characterized by its properties. There are two kinds of properties: Chemical properties describe the abilities of a substance to undergo chemical reactions and to form new substances. Physical properties are qualities such as color, smell, taste, hardness, density, boiling and melting point, the conduction of electricity, and the ability to dissolve other materials.The physical states of matter, sometimes …

  Nature and Scope of Chemistry Chemistry: is the study of matter and the changes that matter undergoes. Matter is made up of almost infinitesimally small building blocks called atoms. Atoms can combine together to form molecules. Molecules of a few familiar substances are represented here. In later chapters you will learn more about how atoms combine to form molecules, and how molecules have the …

استخلاص Extraction : عملية فصل بين مكونات مزيج من المواد السائلة أو الصلبة تعتمد على الاختلاف بين ذوبانية هذه المكونات و تتحقق بواسطة مذيبات انتقائية . يستفاد منها في الكيمياء التحليلية و تطبق في الصناعات  الكيميائية و النفطية و الصناعات الغذائية و الصيدلانية و في مجالات أخرى أيضا . عملية الاستخلاص داخل المختبر   بوسترات (لوحات) كيميائية بدقة عالية (أكثر …

إنطباق occlusion : التقاط الشوائ من المحلول من قبل جسيمات الراسب،و يلاحظ هذه الظاهرة أثناء النمو السريع للرواسب البلورية.و خلاف للإمتزاز السطحي فإن الشوائب أثناء الإطباق تمتص في كتلة الراسب كلها و راخل بلورته ، و تنسب إلى حالة الإطباق حادثة امتصاص الفلزات للغازات .

التعويم Flotation : في المعالجة المعدنية، طريقة تستعمل لفصل وتركيز الخامات بتعديل سطوحها إلى حالة كارهة للماء أو شغوفة للماء أي أن، السطوح أمّا أن تصدّ أو تجذب الماء. طورت عملية التعويم  على النطاق التجاري في بدايات القرن العشرون لإزالة الدقائق المعدنية الصغيرة جدا و التي كانت سابقا تعزل من خلال الجاذبية الارضية ، و حاليا أصبحت عملية  التعويم الأكثر …