Estructura Atómica y Configuración Electrónica

Study Notes

Atomic Structure

An atom is the fundamental unit of matter. It consists of three types of particles: protons, neutrons, and electrons. These particles combine together to form atoms, which combine further to create molecules that make up all forms of matter.

Subatomic Particles

Protons

Protons are positively charged, lightweight particles found in the nucleus of an atom. They have a mass of approximately 1 amu (atomic mass units).

Neutrons

Neutrons, like protons, are also found in the nucleus of an atom, and they have a mass almost equal to the mass of a proton. However, unlike protons, which carry a positive charge, neutrons have no net electric charge.

Electrons

Electrons are negatively charged, much lighter particles that orbit around the nucleus of an atom. Their mass is equal to 99% of their weight in comparison to protons.

Atomic Number

The atomic number, denoted by Z, is the total number of protons found in an atom's nucleus. This property uniquely defines each element. For example, hydrogen has 1 proton, helium has 2 protons, lithium has 3 protons, etc.

Electron Configuration

The arrangement of electrons in an atom's energy levels, or shells, is known as its electron configuration. Each electron occupies a specific orbital within these shells, with multiple electrons allowed for certain orbitals before moving to the next one. The Pauli exclusion principle dictates that only two electrons can exist in any given orbital, and those electrons must have opposite spins.