Electrostatic pressure: what is it and what are its characteristics?

Understanding electrostatic pressure helps us explain the behavior of electricity.

The world of electricity is an exciting one. From the functioning of a battery to the emission of neurons inside the human body, this set of physical phenomena related to the presence and flow of charges allows us, as living beings, to think, move and exist.

On a social level, electricity has also provided us with an inestimable amount of resources: transportation, lighting, air conditioning and computing, which is an understatement to say the least.

It is very curious to know that every living cell in our body has an electrical charge of its own.. As the concentration of salts is different in the intracellular and extracellular medium (calcium, chlorine, sodium, potassium, etc.) an electrical charge and potential difference is established between both media, a term known as "membrane potential".

The variation in membrane potentials in body cells allows us to think (electrical synapse at neuronal level) to contract a voluntary muscle, due to the transmission of action potentials and hyperpolarization or depolarization in each specific process. As you can see, electricity is much more than just a battery: stay with us and find out all about electrostatic pressure..

What are the basics of electrostatics?

Electrostatics is defined as the branch of science that studies the mutual effects that occur between bodies as a result of their electric charges.. All objects on Earth are composed of atoms, the smallest constituent units of matter with the properties of a chemical element. At rest, the positive charges of the atomic nucleus (99.94% of the total weight) are balanced by the negative charges of the surrounding electrons, so the object is considered to be at rest.

When an atom loses or gains electrons, it acquires a positive or negative electric charge. By common convention, when an atom loses one or more electrons it is considered "positively charged" (since protons have a positive charge and are more in number than negative electrons), while if the atom integrates electrons, it becomes negatively charged. From this point on, both are called ions, either positive or negative.

When an atom or molecule acquires a charge, it is automatically influenced by electromagnetic fields and generates them itself.. Based on this premise, we can describe many Biological phenomena, such as chemical bonds. For example, the ionic bond, which consists of the transmission of electrons from a metallic atom (less electronegative) to non-metallic atoms (more electronegative).

What is electrostatic pressure?

Going into the subject, we are afraid that we cannot give you a very exact definition of this term, as it seems to be slightly out of use in the scientific community. Various portals use the word "electrostatic pressure" to designate the electric force of attraction or repulsion between particles with different or identical electric charge, respectively.

If we accept this term, we will see that the most correct way to refer to this electrostatic phenomenon is "electric force".. The electric force or electrostatic pressure will be, then, the force that appears between two or more charges, whose modulus depends on the value of the charges and the distance that separates them (and the sign depends on each charge). This terminological conglomerate can be summarized in the following points:

• Charged atoms or molecules undergo a force of attraction or repulsion when approaching each other. Two ions with the same charge repel each other, but if one is positive (+) and one is negative (-) they approach each other.
• The value of the electrostatic force or pressure is proportional to the product of the value of their charges.
• On the other hand, the value of this force is inversely proportional to the square of the distance separating the charged atoms and acts in the direction of the straight line that joins them.

As of today, these postulations in the field of physics fall under the umbrella of Coulomb's Law, enunciated by the French physicist Charles-Augustin de Coulomb in 1785.enunciated by the French physicist Charles-Augustin de Coulomb in 1785. These postulations can be summarized in the following formula:

In this formula, F refers to the total electric force or electrostatic pressure, k is Coulomb's constant, q1 and q2 are the values of the charges of the atoms mentioned (in coulombs) and r the distance between both charges in meters squared. As a note, it should be noted that the unit "coulomb" or "coulomb" is defined as the amount of charge carried in one second by a current of one ampere of electric current intensity.

The result sought (F) represents the force of attraction or repulsion in Newtons between the two electrically charged atoms or molecules.. The electric force or electrostatic pressure is a vector magnitude, so, in addition to calculating the modulus, its direction and sense must also be estimated. If we have only two atoms in play, the direction of the electric force will be in line with the straight line joining both charges. On the other hand, depending on the sign of the atom, the direction can be of attraction (+/-) or repulsion (+/+, -/-).

Based on all these premises, a series of conclusions can be drawn that are as clear as they are fascinating: charges with the same sign experience an electric force that tends to separate them, charges with a different sign undergo a force that tends to unite them and, the closer the charged atoms are, the greater the modulus of the electric force of attraction or repulsion.

Limitations of Coulomb's law

Although it was a revolution in its day and is still in force today, it should be noted that Coulomb's law also has certain limitations.. Among them, we find the following:

• The charges must have a spherically symmetrical distribution.
• The charges must not overlap.
• The charges must be stationary with respect to each other.
• For very small distances (on the order of the size of atoms), the electrostatic force is overcome by other forces, such as the strong or weak nuclear forces.

The biological utility of electrostatic pressure

The fact that there are positive and negative atoms is not only useful at the level of biological knowledge.. For example, ions are essential in the functioning of biological systems, both muscular and neurological, and in all organic workings. Let's see a concrete case in which the electric potential is transformed into tangible acts.

When a muscle is at rest, the forces of attraction between the actin and myosin that compose it are inhibited. If we develop the desire to perform a specific movement (such as frowning), we emit an action potential (an electrical discharge wave) in the brain that travels through neuronal synapses to the membrane of the motor neuron (motoneuron) related to the muscle we wish to contract.

These electrical potentials cause the motor neuron to release a chemical message to the muscle tissue, transforming this order into the release of acetylcholine which binds to the receptors of the muscle membrane. This membrane potential change at the muscle surface allows the opening of ion-dependent channels within the cells.which results in a massive influx of calcium ions (Ca 2+) after a series of steps, changing the conformation of muscle actin and myosin and allowing contraction.

Summary

As you can see, electrostatic pressures or electrical forces are everywhere. Electricity not only modulates the behavior of a light bulb or a battery, but in the broadest sense of the word, it allows us to transmit nerve signals to all parts of our body and to all parts of our body. to all parts of our body and respond to environmental stimuli in the most efficient way possible.

In the end, everything is a game of charges: atoms or molecules with the same charge repel each other, while those with different charges are attracted, ideally with a force in a linear direction that will be greater the closer the two bodies are. With these premises, we can describe bonds such as ionic and covalent bonds or the very potential of cell membranes, hence life itself and the atomic organization of living beings. Undoubtedly, without electricity we are nothing.