Understanding Atoms

Atoms are defined as the smallest component of an element that still retains the element’s properties. Each atom is made up of a central nucleus with protons (positively charged), neutrons (neutral) and electrons (negatively charged) rotating around it. The electrons rotate within specific areas or layers, known as shells.

There are a certain number of shells in each atom and they are labeled either with numbers, 1-7, or letters, K-Q. Each shell has subshells that can hold only a limited amount of electrons. For example the subshells can carry a maximum of 2 electrons, the next shell up can carry up to 6, etc. Every element is different and has different numbers of electrons in the shells. Not all the shells need to be filled. For example, hydrogen has just one electron, so it can only place that in one shell. Other, more complex atoms, such as Dubnium, fill all their shells with electrons.

The further the electrons are from the nucleus, the more energy they have. The outermost shell is called a valence and this is where we can tell if a chemical compound is reactive or not.

When the valence shell has all of the electrons it can hold, the atom will be extremely stable. Noble gases are a good example of this atomic makeup. However, if there is only one electron in the valence shell, that means the atom will be very reactive. The atoms are constantly trying to balance things out, so if there is space for more electrons in the valence shell, the atom will try to grab more from other atoms. This makes it very easy for these types of atoms to bond together to form new compounds.

There are still ongoing studies to try and understand everything that goes on in an atom. Despite being the smallest particle of matter, it is infinitely complex.