How do atomic models explain chemical reactions?

Atomic models explain chemical reactions by illustrating how atoms interact, bond, and rearrange to form new substances.

Atomic models are fundamental in understanding chemical reactions. They provide a visual representation of atoms, the smallest unit of matter, and their subatomic particles - protons, neutrons, and electrons. The protons and neutrons are located in the nucleus at the centre of the atom, while the electrons orbit the nucleus in energy levels, also known as shells.

Chemical reactions occur when atoms interact with each other. This interaction is primarily due to the behaviour of the electrons in the outermost shell, also known as the valence shell. If the valence shell of an atom is not full, it tends to react with other atoms to fill or empty its shell, achieving a stable electron configuration. This is the driving force behind chemical reactions.

In a chemical reaction, atoms form bonds with other atoms to create new substances. There are two main types of bonds: ionic and covalent. Ionic bonding occurs when one atom transfers one or more electrons to another atom. This results in positively and negatively charged ions, which attract each other to form an ionic compound. Covalent bonding, on the other hand, occurs when two atoms share one or more pairs of electrons. This sharing of electrons allows each atom to achieve a stable electron configuration.

Atomic models also illustrate how atoms rearrange during a chemical reaction. In a chemical equation, the reactants (the starting substances) are converted into products (the resulting substances). The atomic model shows that in this process, the atoms in the reactants are rearranged to form the products, but the total number of each type of atom remains the same. This principle is known as the law of conservation of mass.

In summary, atomic models are a powerful tool in explaining chemical reactions. They show how atoms interact, bond, and rearrange to form new substances, providing a clear picture of the microscopic world that underlies the macroscopic changes we observe in chemical reactions.