Name: atomic charges, bonds, and compounds
Uploaded: 2023-06-23T15:38:43.000Z
Duration: 1 min 23 s
Channel: JoVE

Los iones son átomos cargados eléctricamente que han ganado o perdido electrones. Un átomo que pierde electrones y se carga positivamente es un catión, mientras que un átomo que gana electrones y se carga negativamente es un anión.
Los iones son vitales para muchos procesos fisiológicos, como la transmisión de impulsos nerviosos y la contracción muscular.
Las moléculas son combinaciones de dos o más átomos que comparten electrones. Pueden estar formados por átomos de un elemento, como una molécula de oxígeno, o átomos de diferentes elementos, como una molécula de agua.
Un compuesto es una combinación de átomos de diferentes elementos unidos químicamente en una proporción fija, independientemente de si los electrones se transfieren o se comparten.
Los compuestos iónicos se forman por interacción electrostática entre iones metálicos y no metálicos, como en la sal de mesa ordinaria, con un catión de sodio y un anión cloruro unidos entre sí mediante interacciones electrostáticas.
Los compuestos moleculares se forman cuando los átomos no metálicos se unen a través de enlaces covalentes. Por ejemplo, el metano es un compuesto molecular en el que cuatro átomos de hidrógeno comparten electrones con un átomo de carbono en una proporción específica.

iones, moléculas y compuestos

Los iones: cuando un átomo participa en una reacción química que resulta en la donación o aceptación de uno o más electrones, el átomo se carga positiva o negativamente. Esto ocurre frecuentemente para la mayoría de los átomos para tener una capa de valencia completa. Esto puede ocurrir ya sea ganando electrones para llenar una capa que está más de "medio llena" o dando electrones para vaciar una capa que está menos de "medio llena", dejando así la siguiente capa de electrones más pequeña como la nueva capa de valencia completa. Un átomo con una carga eléctrica, positiva o negativa, es un ion.

El potasio (K), por ejemplo, es un elemento importante en todas las células del cuerpo. Su número atómico es 19. Tiene solo un electrón en su capa de valencia. Esta característica hace que el potasio sea muy probable de participar en reacciones químicas en las que dona un electrón. La pérdida hará que la carga positiva de los protones de potasio sea más influyente que la carga negativa de los electrones de potasio. En otras palabras, el ion de potasio resultante será ligeramente positivo. Un ion cargado positivamente se conoce como un catión.

Otro elemento, el flúor (F), un componente de los huesos y los dientes, tiene un número atómico de nueve. Tiene siete electrones en su capa de valencia. El flúor es muy probable que se una con otros átomos de tal manera que acepte un electrón. Cuando lo hace, sus electrones superarán en número a sus protones en uno, y tendrá una carga neta negativa. Un ion cargado negativamente se conoce como un anión.

Los iones son fundamentales para el funcionamiento normal del cuerpo, por lo que sus desequilibrios pueden conducir a problemas de salud. Por ejemplo, un desequilibrio del ion de sodio podría causar enfermedades cardiovasculares. Los niveles bajos de calcio en la sangre pueden causar tetania, contracciones musculares involuntarias incontrolables.

Las moléculas: las moléculas son simplemente dos o más átomos unidos químicamente. Las moléculas pueden consistir en átomos del mismo elemento, como una molécula de gas oxígeno, formada por la unión entre dos átomos de oxígeno, respectivamente, o las moléculas pueden formarse por la unión entre átomos de diferentes elementos, como una molécula de gas dióxido de carbono, formada entre átomos de oxígeno y carbono.

Los compuestos: un compuesto es una sustancia pura formada por la unión de dos o más átomos en una proporción fija. Por ejemplo, el compuesto glucosa es un combustible importante para el cuerpo. Siempre está compuesto por los mismos tres elementos: carbono, hidrógeno y oxígeno, en las mismas cantidades relativas. En la glucosa, siempre hay seis unidades de carbono y seis unidades de oxígeno por cada doce unidades de hidrógeno.

Este texto está parcialmente adaptado de <a href="https://openstax.org/books/anatomy-and-physiology-2e/pages/2-2-chemical-bonds?query=when%20a%20atom%20participates&target=%7B%22type%22%3A%22search%22%2C%22index%22%3A0%7D#fs-id2113058">Openstax, Anatomy and Physiology 2e, Section 2.2 Chemical Bonds</a> and Openstax, <a href="https://openstax.org/books/anatomy-and-physiology-2e/pages/2-1-elements-and-atoms-the-building-blocks-of-matter?query=For%20example%2C%20the%20compound%20glucose%20is%20an%20important%20body%20fuel.%20It%20is%20always%20composed%20of%20the%20same%20three%20elements&target=%7B%22type%22%3A%22search%22%2C%22index%22%3A0%7D#fs-id1882474">Anatomy and Physiology 2e, Section 2.1 Elements and Atoms: The Building Blocks of Matter</a>.

Iones, Moléculas y Compuestos

Iones: cuando un átomo participa en una reacción química que resulta en la donación o aceptación de uno o más electrones, el átomo se vuelve positivamente ...

Education

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JoVE Core

Anatomy and Physiology

Anatomía y Fisiología

Unit 1

Unidad 1

Fundamentals of Chemistry

Fundamentos de Química

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Ions, Molecules, and Compounds

atomic charges, bonds, and compounds

Atoms can gain or lose electrons during chemical reactions and become ions. An ion is an atom with an electrical charge. This charge is positive or negative, and it often helps the atom reach a full valence shell.

Some atoms are more likely to donate electrons, while others are more likely to accept them. Potassium is one example. It has atomic number 19 and one electron in its valence shell, so it is likely to donate that electron and become a slightly positive ion called a cation. Fluorine is another example. It has atomic number 9 and seven electrons in its valence shell, so it is likely to accept one electron and become a negatively charged ion called an anion.

Ions are important for normal body function, so an imbalance can cause health problems. A sodium ion imbalance can contribute to cardiovascular diseases. Low blood calcium levels can also cause tetany, which is marked by uncontrollable involuntary muscle contractions.

Molecules and compounds are related but not the same. A molecule is two or more atoms chemically bonded together. The atoms may be the same element, as in oxygen gas, or different elements, as in carbon dioxide gas. A compound is a pure substance made when two or more atoms bond in a fixed proportion.

Glucose is a useful example of a compound. It is an important body fuel and always contains the same elements in the same relative amounts: carbon, hydrogen, and oxygen. In glucose, there are always six carbon units and six oxygen units for every twelve hydrogen units.

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anatomy and physiology

JoVE Core Anatomy and Physiology showcases the anatomical and physiological details of the human body in comprehensive, clear, and engaging video animations. This collection of lessons focuses on the structures, components, functions, and requirements of the human body. It is complemented by scientist-in-action videos that demonstrate the application of this knowledge in real-world medical and research settings.

Atomic Charges, Bonds, and Compounds

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