The periodic table is a list or arrangement of all known chemical elements. These are organized in a way that it allows grouping elements with similar atomic structure, and therefore, similar properties. The main criteria for this order is the arrangement by increasing atomic number, which is the number of particles of that element’s nucleus (protons and neutrons). It’s invention is attributed to the Russian chemist Dimitri Mendeleev, and in 2019 we celebrate the 150 anniversary of his original report in 1869.
There are three basic types of chemical compounds, and should be briefly introduced in this post about basic chemistry concepts. All of them are the result of bonding atoms together. The difference is in the nature of the forces that hold together those atoms.
In molecules (such as water, or H2O, see above), which are neutral compounds of “individual” nature, atoms are glued together by covalent bonds. Covalent bonds generally occur between two non-metal atoms, which share pairs of electrons, or bonding pairs.
In ionic compounds (such as sodium chloride, or NaCl, commonly known as “salts”), atoms are in ionic form (charged) and are held together by ionic forces, giving rise to large networks of oppositely charged ions. Ionic bonds occur between metals and non-metals.
When extended networks of atoms are formed between one or more types of metal atoms, we are talking about metallic bonds.
A molecule is a group of atoms bound together. It’s the next level of chemical complexity. Molecules represent the basic unit of a chemical compound, and this another of those essential basic chemistry concepts.
That’s basically it. An example is a water molecule, which is made from two atoms of hydrogen (H) and one atom of oxygen (O), held together via covalent bonds.
Models of a water molecule. Credit to Dbc334/Jynto via Wikipedia
Further definitions include, that they are the simplest fundamental unit that can take part in a chemical reaction, and that they are electrically neutral. This latter point distinguishes molecules from ions, another type of chemical compound.
An atom is defined as the basic unit of a chemical element. A fundamental piece of matter. Plain simple and basic chemistry concept.
Obviously we now know that atoms are made of smaller particles, called subatomic particles: protons (positively charged by convention), electrons (negatively charged by convention) and neutrons (neutral particles).
In simple terms: Protons and neutrons make up the inner part of the atom, or nucleus, and account for most of the mass of the atoms. Electrons make up a cloud (orbitals, or areas in which the probability of finding an electron is high) around the nucleus.
Bohr model of an atom, via universetoday.com
Protons and neutrons are not fundamental particles; they are made of quarks. On the other hands, as far as we known, electrons are fundamental particles and they are not made of anything smaller.
Chemistry is the science that studies and manipulates matter. We human beings are getting pretty good at it, (although it is not easy to beat Nature), but we are far from an ideal position in which we can easily make any molecule or compound at will in a matter of minutes.
That is probably the future of chemical synthesis, being able to shape any compound at will in a matter of minutes, without relying on long term challenging synthesis projects. Furthermore, the possibilities of synthetic chemistry are literally endless: there will always be room for making a chemical even better, or finding a molecule that works even better for a given task.
Another key aspect of the “chemistry of the future” will be reaching true full sustainability. Chemistry will be one of the main branches of science to solve the problem of energy.
Also, chemistry, as the central science, will be responsible to helping technology and interdisciplinary science in general to develop smoothly.
Chemistry, the central science, holds interdisciplinary technologic advances together. Credit to NASA/Pat Rawlings.
A all sciences are glued together by basic chemistry concepts, thats why it is called the central science. Without chemistry, physical sciences (which include chemistry itself), would find a gap and not be bound to life sciences (such as biology) and applied sciences (such as engineering). This is important to note in any introduction to chemistry text.
Everything is chemistry. Everything that you can observe macroscopically is made of chemicals. You are made of chemicals, your food is chemicals, you breathe chemicals, we live out of and thanks to chemicals, everything you see under the sun is a mixture of chemicals.
Everything you see or do is based on chemical concepts and processes. Fireworks going off takes place thanks to our understanding and application of chemistry. A medicine that you take to cure your illness does it so through chemical processes. A building doesn’t fall off because we know chemistry. Obviously, all these examples result from a bunch of different branches of science coming together. Chemistry, as the central science, is in charge of gluing them together.
Very simple chemical processes were performed even during ancient history, at 1000 BC, much before any basic chemistry concepts or laws were actually established. Extraction of metals from ore or getting compounds out of natural sources such as plants, are examples of chemistry that was first performed thousands of years ago and are still a thing today.
Alchemy is what we call the “protoscience” of chemistry.
The Alchemist in Search of the Philosopher’s Stone, by Joseph Wright (1771)
Alchemy tried to explain the nature, properties and transformations of matter. But it was not science, but rather a set of myths and magic. It is agreed upon that, the transition from alchemy to modern chemistry as we know it, started on the 17th century, with the publication of The Sceptical Chymist by Robert Boyle (1661), who is considered the father of modern chemistry. The difference between chemistry and alchemy is the application of the scientific method.
As an introduction to chemistry, it is the branch of science that studies matter and change. First, chemistry deals with the study of the composition and the properties of matter (which is basically any macroscopic substance that we can observe). Then, chemistry deals with change, or how these substances evolve when submitted to certain conditions, or how one substance changes or reacts while interacting with a different substance. The definition of chemistry can’t be made shorter, since it covers basically everything!
