جميع المواضيع المتعلقة بـ ‘Atom’

 

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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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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ملخص الفصل الثاني :الذرات و الجزيئات و الأيونات من كتاب الكيمياء للعالم زومدال Chapter 2 notes: Atoms , molecules and ions , AP chemistry Zumdahl

ملخص الفصل الثاني :الذرات و الجزيئات و الأيونات من كتاب الكيمياء للعالم زومدال Chapter 2 notes: Atoms , molecules and ions , chemistry Zumdahl

 

 

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Structure of the Atom

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 called neutrons Negatively charged electrons

– Protons and neutrons…

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Atomic Theory

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.

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Conservation of Mass and Atoms

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 of the water that they form. Furthermore, the…

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ذرة

ذرة Atom :

الذرة هي أصغر جزء من العنصر الذي يمكن أن يتواجد كيميائيا أي بمعنى أخر الذرات هي القوالب البنائية للعناصر الكيميائية مثل الهيدروجين و الأكسجين و الكربون و غيرها . وتتفاوت الذرات كثيرًا في الوزن، ولكنها جميعًا تتساوى تقريبًا في الحجم فمثلا ذرة اليورانيوم تعتبر أثقل الذرات الموجودة في الطبيعة و لكن حجمها لا يتعدى…

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