Name: how atoms bond to reach stability
Uploaded: 2023-06-23T15:38:43.000Z
Duration: 1 min 1 s
Channel: JoVE

تحافظ الروابط الكيميائية على ذرات الجزيء أو المركب معا. تتشكل الروابط عندما يتم التبرع بالإلكترونات الموجودة في غلاف تكافؤ الذرة أو مشاركتها مع ذرات أخرى.
على سبيل المثال ، تتشكل الروابط الأيونية عندما تتبرع الذرات أو تقبل الإلكترونات ، وتملأ غلاف التكافؤ الخاص بها. الذرة التي تتبرع بالإلكترونات وتصبح موجبة الشحنة هي كاتيون ، في حين أن الذرة التي تقبل الإلكترونات وتصبح سالبة الشحنة هي أنيون.
في ملح الطعام ، الارتباط بين كاتيون الصوديوم وأنيون الكلوريد هو رابطة أيونية.
تتشكل الروابط التساهمية بين الذرات التي تشترك بشكل متبادل في زوج واحد أو أكثر من إلكترونات التكافؤ.
على سبيل المثال ، يمكن لذرتين من الهيدروجين أن تشترك في زوج من الإلكترونات ، مما يشكل رابطة تساهمية واحدة. يمكن أن يشترك الأكسجين والنيتروجين في زوجين وثلاثة أزواج من الإلكترونات ، مما يشكل روابط مزدوجة وثلاثية.

مقدمة عن الروابط الكيميائية

Introduction to Chemical Bonds

<div style="direction:rtl">الروابط الكيميائية

تُحدِّد إلكترونات مستوى الطاقة الخارجي الاستقرار الطاقوي للذرة وميلها لتكوين روابط كيميائية مع الذرات الأخرى. تبلغ السعة القصوى للغلاف الإلكتروني الداخلي إلكترونين، لكن الغلافين الإلكترونيين التاليين يمكن أن يحتوي كل منهما على ثمانية إلكترونات كحد أقصى. ويُعرف هذا بقاعدة الثمانيات، التي تنص على أنه باستثناء الغلاف الأعمق، تكون الذرات أكثر استقرارًا من الناحية الحيوية عندما يكون لديها ثمانية إلكترونات في غلاف التكافؤ، وهو الغلاف الإلكتروني الخارجي.

لكن بما أن جميع العناصر لا تحتوي على إلكترونات كافية لملء أغلفتها الخارجية، فإن الذرات تشكل روابط كيميائية مع ذرات أخرى، وبذلك تحصل على الإلكترونات التي تحتاجها للوصول إلى توزيع إلكتروني مستقر. ومن ثم، فإن الروابط الكيميائية هي القوة التي تربط الذرات معًا في جزيء أو مركب. الروابط الأيونية

يمكن أن تكتسب الذرات إلكترونات أو تفقدها لملء غلاف التكافؤ. وبذلك، تصبح الذرات مشحونة كهربيًّا وتُسمَّى أيونات. الكاتيون هو ذرة موجبة الشحنة تفقد إلكترونات، في حين أن الذرة التي تكتسب إلكترونات وتصبح سالبة الشحنة تسمى الأنيون. تؤثر الشحنات المتعاكسة للكاتيونات والأنيونات على تجاذب متبادل قوي إلى حد ما يبقي الذرات على مقربة من بعضها البعض مكونة رابطة أيونية. الرابطة الأيونية هي ارتباط مستمر وقريب بين أيونات ذات شحنات متعاكسة. يعود الفضل في وجود ملح الطعام الشائع إلى الرابطة الأيونية. الروابط التساهمية ثمة طريقة أخرى يمكن من خلالها تحقيق قاعدة الثمانيات وهي مشاركة الإلكترونات بين الذرات لتكوين روابط تساهمية. هذه الروابط أقوى وأكثر شيوعًا من الروابط الأيونية في جزيئات الكائنات الحية. توجد الروابط التساهمية عادةً في الجزيئات العضوية القائمة على الكربون، مثل الحمض النووي والبروتينات. كما توجد الروابط التساهمية أيضًا في الجزيئات غير العضوية مثل الماء وثاني أكسيد الكربون والأكسجين. الروابط الهيدروجينية تتكوَّن الرابطة الهيدروجينية عندما تنجذب ذرة هيدروجين ضعيفة الموجبة مرتبطة بالفعل بذرة ذات سالبية كهربية (على سبيل المثال، الأكسجين في جزيء الماء) إلى ذرة أخرى ذات سالبية كهربية من جزيء آخر. يحدث المثال الأكثر شيوعًا للرابطة الهيدروجينية في العالم الطبيعي بين جزيئات الماء. ويحدث ذلك عندما تندمج قطرتا مطر في حبة أكبر أو عندما يتدفق جدول ماء في نهر. يحدث الترابط الهيدروجيني لأن ذرة الأكسجين السالبة الضعيفة في أحد جزيئات الماء تنجذب إلى ذرات الهيدروجين الموجبة الضعيفة في جزيئين آخرين من الماء.

هذا النص مقتبس جزئيًا من <a href="https://openstax.org/books/anatomy-and-physiology-2e/pages/2-2-chemical-bonds?query=chemical%20bond&target=%7B%22type%22%3A%22search%22%2C%22index%22%3A0%7D#fs-id1493624">Openstax ، Anatomy and Physiology 2e ، الفصل 2.2: الروابط الكيميائية.</a> <a href="https://openstax.org/books/biology-ap-courses/pages/2-1-atoms-isotopes-ions-and-molecules-the-building-blocks?query=chemical%20bonds">Openstax , </a><a href="https://openstax.org/books/biology-ap-courses/pages/2-1-atoms-isotopes-ions-and-molecules-the-building-blocks?query=chemical%20bonds">Biology for AP® Courses</a><a href="https://openstax.org/books/biology-ap-courses/pages/2-1-atoms-isotopes-ions-and-molecules-the-building-blocks?query=chemical%20bonds"> الفصل </a><a href="https://openstax.org/books/biology-ap-courses/pages/2-1-atoms-isotopes-ions-and-molecules-the-building-blocks?query=chemical%20bonds">2.1 الذرات، النظائر، الأيونات والجزيئات: كتل البناء.</a></div>

الروابط الكيميائية
تحدد إلكترونات مستوى الطاقة الخارجي الاستقرار النشط للذرة وميلها إلى تكوين روابط كيميائية مع ...

Education

JoVE Core

Anatomy and Physiology

التشريح وعلم وظائف الأعضاء

Unit 1

الوحدة الأولى

Fundamentals of Chemistry

أساسيات الكيمياء

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الأساسية

how atoms bond to reach stability

Atoms bond to become more stable, and their outermost electrons play the biggest role in that process. The inner electron shell can hold two electrons. The next two shells can each hold eight electrons. This is called the octet rule. It states that, except for the innermost shell, atoms are most stable when their valence shell, or outer shell, has eight electrons.

When atoms do not have enough electrons to fill that outer shell, they form chemical bonds with other atoms. A chemical bond is the force that holds atoms together in a molecule or compound. These bonds let atoms reach a more stable electron arrangement.

One common type is an ionic bond. In this case, atoms gain or lose electrons to fill their valence shell. When they do this, they become ions. A cation is a positively charged ion that has lost electrons. An anion is a negatively charged ion that has gained electrons. The opposite charges attract each other and keep the ions close together. This close association forms an ionic bond. Table salt is a common example of a substance made through ionic bonding.

Another way atoms satisfy the octet rule is by sharing electrons. This creates covalent bonds. Covalent bonds are stronger and much more common than ionic bonds in the molecules of living organisms. They are found in carbon-based organic molecules such as DNA and proteins. They also occur in inorganic molecules like water, carbon dioxide, and oxygen.

Hydrogen bonds are a weaker kind of attraction. They form when a weakly positive hydrogen atom, already bonded to another electronegative atom such as oxygen, is attracted to a different electronegative atom in another molecule. Water is the most common example. Hydrogen bonding helps explain why raindrops can merge into larger beads and why a creek can flow into a river.

How Atoms Bond to Reach Stability

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introduction to chemical bonds

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ionic bonds

Ionic Bonds and Charge Transfer

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hydrogen bonds

Hydrogen Bonding and DNA Stability

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How Atoms Bond to Reach Stability | JoVE K12

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How Atoms Bond to Reach Stability

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