The observation of chemical reactions and bonds at the molecular level allows us to understand the fundamentals of bond energy.
Bond energy is the amount of energy needed to break down a chemical bond in a compound, separating its atoms into individual, gaseous states. This concept is fundamental in chemistry and nuclear physics, since it allows us to understand the stability of molecules and atomic nuclei. Bond energy is generally measured in kilojoules per mole (kJ/mol) and can vary depending on the type of bond and the properties of the atoms involved.
Examples of binding energy
Molecular hydrogen bond energy
In the case of the hydrogen molecule, the binding energy is approximately 436 kJ/mol . This is the energy required to break the covalent bond between two hydrogen atoms and completely separate them into individual atoms in the gaseous state.
Binding energy in water
The water molecule contains bonds between oxygen and hydrogen, whose bond energy is approximately 463 kJ/mol . This amount of energy must be supplied to break the OH bonds and convert water into individual oxygen and hydrogen atoms.
Binding energy in molecular oxygen
In diatomic oxygen, the binding energy is about 498 kJ/mol . This value indicates the energy required to dissociate a double bond between the oxygen atoms in this gas molecule.
Nuclear binding energy in helium
In the context of nuclear binding energy, the helium nucleus has a high binding energy per nucleon, which explains its great stability. The nuclear binding energy here is much higher than in chemical bonds and is measured in megaelectronvolts (MeV) per nucleon.
Nature of chemical bonds
Chemical bonds are forces that hold atoms together in molecules or crystalline networks, allowing the formation of compounds. The three main types are defined below.
covalent bond
It occurs when two atoms share one or more pairs of electrons. It is characteristic of non-metallic elements and is observed, for example, in molecules such as water or oxygen. Covalent bonds can be single, double or triple, depending on the number of electrons shared.
ionic bond
In this type of bond, one atom gives up electrons to another, forming oppositely charged ions that attract each other. Ionic bonding is common in compounds between metals and non-metals, such as sodium chloride, where sodium gives up an electron to chlorine, forming a strong bond in the crystal lattice of the compound.
Metal link
It takes place in metals, where the valence electrons form a cloud of free electrons that move between the positive nuclei. This sea of electrons gives metals their electrical conductivity and their ability to deform without breaking, as occurs in copper or iron.
The structure of atomic and molecular bonds defines the properties and energies of the molecules.
Theoretical foundations
Bond energy is determined by various interactions and theories that explain how bonds between atoms are formed and maintained.
Van der Waals forces
Weak intermolecular forces that act between neutral molecules, contributing to the bond energy in large molecules or in networks of non-covalent compounds. Although much weaker than covalent or ionic bonds, these attractive forces (such as London dispersion and dipole-dipole interactions ) play an important role in the structure and properties of many compounds.
atomic orbitals
They describe the regions with the highest probability of finding an electron around an atomic nucleus. The arrangement and shape of these orbitals (s, p, d, f) determine how bonds between atoms overlap and form, as electrons tend to pair up in these specific spaces to minimize the energy of the system.
Molecular orbital theory
It suggests that when atoms come together to form a molecule, their atomic orbitals combine to form molecular orbitals, which extend over the entire molecule. These can be bonding or antibonding, and their occupation by electrons directly influences the energy and stability of the bond.
Heisenberg uncertainty principle
According to this fundamental principle of quantum mechanics, it is impossible to precisely know the position and momentum of an electron. This implies that the electrons are found in probability regions, which is key for the formation and stability of the bonds, since the electrons are distributed in orbitals that minimize the total energy of the system without their position being completely defined.
Nuclear energy and atomic reactions
Nuclear binding energy plays a fundamental role in understanding processes such as nuclear fission and nuclear fusion, both mechanisms where an enormous amount of energy is released or absorbed due to the rearrangement of subatomic particles in the nucleus of atoms. .
The strong nuclear force , the interaction that holds protons and neutrons together, is crucial to the stability of the nucleus. This force, despite being effective only at extremely short distances, overcomes the electrostatic repulsion between positively charged protons, allowing the nucleus to remain compact and stable.
The stability of a nucleus depends directly on its internal configuration, which is modeled through different theoretical approaches, known as nuclear models . These models attempt to explain the behavior and energy of nuclei, thus allowing us to predict the behavior of atoms in nuclear reactions. Nuclear magnetic resonance (NMR) , a technique derived from the study of binding energy, is used to observe how nuclei react to magnetic fields, being widely applied in medicine and chemical research.
These concepts together explain both nuclear stability and how binding energy affects the energy processes of the universe, from the power of stars through fusion to the applications of fission in nuclear reactors.
Renewable energies, such as solar and wind, represent the use of energy in clean and sustainable ways.
forms of energy
Each type of energy, whether potential, kinetic or from renewable resources, plays a role in the transition towards a cleaner energy matrix and in the efficient use of the planet's resources.
Potential energy
Energy manifests in multiple forms in the universe, each with specific characteristics and applications. Potential energy is the energy stored in an object due to its position or configuration, and is transformed into kinetic energy when this object moves. This transformation is fundamental in natural processes and in technologies such as hydroelectric energy , where water stored in reservoirs acquires kinetic energy as it falls, generating electricity.
Renewable energy
Solar energy , wind energy and geothermal energy stand out as sustainable sources that use natural resources efficiently. Solar energy converts light into electricity using photovoltaic cells, while wind energy transforms the kinetic energy of the wind into electricity, and geothermal energy uses the Earth's internal heat to generate energy.
Energy and chemical processes
In this area, ionization energy and activation energy stand out. The first is the energy required to remove an electron from an atom or molecule, a process that is key in electrical conduction and chemical reactions. On the other hand, the activation energy is the minimum necessary for a chemical reaction to occur, controlling the speed of reactions in natural and artificial processes.