What exactly is the periodic table of elements?
The periodic table of elements is a system used to organize all the chemical elements in which the elements are arranged in order of increasing atomic number.
The periodic system groups together all the known elements on earth in order to make it easier for people to track the properties of different elements. The set-up of the table inherently groups together elements with similar properties.
The properties of the elements are reflected in their group, or the column in which they are a part of. For example, all the elements in the first column of the table on the far left all have similar properties, they are all relatively soft metals, whereas the elements in the last column on the far right side of the periodic table are all unreactive gasses at room temperature.
Understanding the periodic table and the periodic elements within the table is an integral skill for science students.
What is the history of the periodic table?
The most important initial version of the periodic table was first established in 1869 by chemist Dimitri Mendeleev. His initial version of the periodic table arranged the elements in order of atomic masses as the nucleus of atoms had not yet been discovered.
As knowledge about atoms and elements evolved, it became clear that it made more sense to arrange the periodic table by atomic number as this told us the most about the properties of each element. In Mendeleev’s first periodic table, there were spaces left clear as he anticipated more elements would be discovered.
Mendeleev was correct in guessing that more elements would be discovered, as new elements have been discovered as recently as 2016. In order to accommodate these additional elements, the International Union of Pure and Applied Chemistry was established to standardize these new developments and integrate them into the periodic table.The organization is also responsible for updating information surrounding the periodic table, such as updating atomic weights and other such information.
Understanding the periodic table of elements
Reading the periodic table is something that a lot of students struggle with. Walking through the sections of the periodic table and the periodic system can help individuals understand the periodic table of elements, which can be done with professional tutors to ensure students grasp the concept. If students can understand how to read the periodic table, it can unlock access to other integral areas of science, specifically chemistry.
There are three important aspects of the periodic table that are essential to understand: the atomic number, the atomic symbol and the atomic weight.
Atomic Number
The atomic number of an element refers to the number of protons in the element. The protons are found in the atomic nucleus of each individual element. It is also important to remember that each atom has the same number of protons and electrons. Therefore, if you know that the atomic number of sodium is 11, it means it has 11 protons and 11 electrons.
The number of protons in each elemental atom is different, therefore, you will be able to identify each element solely from their atomic number, or the number of protons it has. This means that any atom with the atomic number 11 is sodium, but an atom with the atomic number 12 is no longer sodium. Atoms with this many protons in its nucleus are magnesium.
The atomic number can be found above the element to the left of the atomic symbol. For example, sodium has the atomic symbol of Na, which can be found in the center of the square. In the top left-hand corner is the number 11, which is the atomic number.
Atomic Symbol
The atomic symbol is found in the center of each square in the periodic table. It is the abbreviation used to refer to each of the chemical elements in the periodic table.
The atomic symbol can often be confusing as the letters used do not necessarily coordinate with the name of the element. If we use the previous example of sodium, you might expect the atomic symbol to be S, however, S is the atomic symbol for sulfur, meaning sodium’s atomic symbol is Na. This is one of the most confusing parts of the periodic table, but tutors often have tips and tricks to help you remember the atomic symbols of each element.
The atomic symbol is always written in the same way, the first letter is always capitalized whilst the second letter (if there is one) is always lower-case.
Atomic Weight
The atomic weight, often referred to as the atomic mass, refers to the number on the periodic table that reflects the number of protons and neutrons in the elemental atom.
Similarly to the atomic number, the periodic table is arranged with increasing atomic weight. However, the atomic weight is more erratic than the nice neat increase of the atomic number, and there are a few elements that break this trend. Many weights are decimal numbers, but they are arranged in increasing order from top to bottom.
These are the three main bits of information that can be found on the periodic table. Each chemical element has these three properties which allow you to find out more information about each specific atom and element.
The structure of the periodic table
In addition to the information in each individual square being extremely important, the overall layout of the periodic table is also equally integral to understand. The table is split into rows and columns. The rows are called periods and the columns are known as groups.
All the elements in each group have similar properties which allow them to be grouped together. For example, the metals in the periodic table can be found in group 1 all the way through to group 13, with those sitting between groups 3 and 12 being transition metals. The remaining groups house all the non-metal elements. There are far more metal elements in the periodic table than there are non-metals.
Uses of the periodic table
Many students are reluctant to commit their time to learning about the periodic table as they think this information won’t be of use in the real world. However, it is the role of the tutor to get their student engaged and interested in what they are learning about.
The elements in the periodic table make up absolutely everything in the universe, meaning it couldn’t be more relevant to everyday life. The periodic table allows us to predict the properties of existing elements and therefore understand how each element is going to react to certain conditions.
Possibly more exciting, though, is the ability of the periodic table to predict the properties of elements that have not yet been discovered. Overall, the periodic table is a logistical masterpiece that makes understanding the chemistry and property of existing and future elements as easy as possible.
Ultimately, the periodic table is not an easy concept to grasp, nevertheless it is an integral part of chemistry that must be understood in order to achieve good grades. If you are a student struggling with the concept, hiring a tutor can make your learning experience smoother and more enjoyable!