Atom Structure Basics - Visual Guide for IB Physics

Welcome to our exploration of the basic components of an atom!An atom is made up of three fundamental particles: protons, neutrons, and electrons.Protons have a positive charge of plus one, neutrons have no charge, and electrons have a negative charge of minus one.The size differences between these particles are remarkable. The nucleus, containing protons and neutrons, is incredibly tiny compared to the whole atom.While protons and neutrons cluster in the nucleus at the center, electrons orbit in shells around it.Despite the atom being mostly empty space, the nucleus contains nearly all of its mass.The nucleus is densely packed with protons and neutrons, bound together by the strong nuclear force.In the Bohr model of the atom, electrons orbit the nucleus in specific shells or energy levels.The first shell, also called the K shell, can hold up to two electrons.The second shell, or L shell, can accommodate up to eight electrons.The third shell, the M shell, can hold up to eighteen electrons, though we're showing just a few for clarity.Each shell represents a different energy level. The closer to the nucleus, the lower the energy.When an electron absorbs energy, it can jump to a higher energy level.When the electron returns to a lower energy level, it releases energy, often in the form of light.Remember, while the Bohr model helps us understand electron shells, actual electron behavior is more complex, following quantum mechanical principles.Let's explore how we identify atoms using their atomic number and mass number.The atomic number, represented by Z, is the number of protons in an atom's nucleus.The mass number, represented by A, is the total number of protons plus neutrons.To find the number of neutrons, we subtract the atomic number from the mass number.Let's look at isotopes, which are atoms of the same element with different numbers of neutrons.Carbon-12 has six protons and six neutrons, while Carbon-14 has six protons but eight neutrons.Let's review what we've learned about atomic numbers and mass numbers.Thanks for learning about atomic structure with Spark.E!