La periodic table It is an essential tool for understanding chemistry. In it, the chemical elements They are organized according to their atomic number and other chemical and physical properties. This arrangement facilitates its study and the understanding of the characteristics and behaviors of each element. In addition to its basic function as a chart, the periodic table allows us to establish important relationships between the elements. Therefore, beyond being a simple graph, it is a key tool for understanding how the elements interact with each other and how we can predict their behavior in different chemical situations.
What is the periodic table and what is it for?
As we have mentioned, the periodic table is much more than a simple scheme of organization of elements. It is a graphic representation that allows us to quickly observe both the similarities as differences among the chemical elements. This structure facilitates the comparison of their properties and their practical application. The periodic table is not random: the Elements are arranged from left to right and from top to bottom following a specific pattern. This pattern is defined by the atomic number of each element, which represents the number of protons in the nucleus of the atoms that make up each element. Thus, the arrangement of the elements in the periodic table allows us to group those with similar chemical characteristics. rows Horizontal are called Periodically, while the columns vertical are known as groups o families.
Development of atomic elements, properties and weights
Throughout history, many of the elements we know today were already recognized previously. physical, the high-performance plata, the copper and the mercury are examples of these ancient elements. However, it was not until the 17th century that the first documented discovery of a new element took place. This was the match, discovered by the German alchemist Henning BrandLater, during the 18th century, other elements essential to modern chemistry were discovered, such as hydrogen and the oxygen. At this point in the story, Antoine Lavoisier He created a list of 33 elements that he grouped according to their characteristics as gases, metals, no metals, and landlaying the foundations for the future periodic table. During the 19th century, the English chemist John dalton introduced the idea of ​​a system based on the atomic weight, which allowed scientists to organize the elements in a more precise way. Although his early work was somewhat flawed, Dalton’s contribution was instrumental in the later development of the periodic table model we know today.
Structure of the periodic table and its elements
Currently, the periodic table is composed of a total of 118 items. These elements are distributed in Periodically y groups, Also known as familiesEach of these groups is characterized by including elements with similar physical and chemical properties, which is essential for the study of chemistry.
Groups or families
The groups of the periodic table are arranged in vertical columns and there are a total of 18. Organization in groups is key, since the Elements of the same group tend to share similar propertiesThese similarities are due to the fact that elements in the same group have the same number of electrons in their outermost shell, which influences their behavior in chemical reactions.
- Group 1: Alkali metals. These elements include the Lithium (Li), the sodium (Na) and the potassium (K). These metals are known to be extremely reactive.
- Group 2: Alkaline earth metals. As the Calcium (Ca) and the strontium (Sr). These elements are good conductors of electricity and have greater hardness than the previous ones.
- Group 17: Halogens. This group includes highly reactive elements, such as fluorine (F) and the chlorine (Cl), which are essential in many chemical reactions.
- Group 18: Noble gases. This group is composed of colorless and odorless gases, such as neon (Ne) and the argon (Ar), which do not usually react with other elements due to the stability of their electrons.
Periods
Los Periodically They correspond to horizontal rows that we find in the periodic table. The number of each period tells us how many energy levels has a particular atom. As we move from one period to another in the table, the atoms of the elements contain more energy levels.
- Period 1: Composed of only two elements, the hydrogen (H) and the Helium (He).
- Period 2: This period includes elements such as the Lithium (Li), the carbon (C), and the oxygen (EITHER).
- Period 4: In this period we find elements such as the potassium (K), and the Calcium (AC).
- Period 7: The heaviest and most radioactive elements are found here, such as uranium (OR).
Block divisions
Another fundamental aspect to understand the organization of the periodic table is the division into blocksDepending on which orbital the last electron of an element is located in, we can group the atoms into four different blocks: s, p, d, and f.
- Block s: It corresponds to the first two groups of the periodic table and contains elements such as hydrogen and alkaline metals.
- Block p: It contains six groups, including non-metals and noble gases.
- Block d: Includes transition elements, that is, those that form groups 3 to 12.
- Block f: The lanthanide and actinide elements are grouped here.
What is the importance of the table of elements?
La periodic table It is not just a tool for chemistry students, but a key resource for scientists worldwide. Its usefulness lies in its ability to predict an element’s behavior based on its position in the periodic table. Furthermore, the periodic table provides us with valuable information about each element. At first glance, we can see key elements such as its chemical symbol, its atomic number, and his atomic mass, among others. This information allows us to perform calculations, predict interactions and understand how they will behave in chemical reactions.
How to use the periodic table
Despite how complex it may seem, the periodic table is very easy to use once we understand the basic concepts that organize it. Here are some keys to understanding and using the table correctly:
- Symbols: Each element is represented by one or two characters that define its name in its original language.
- Atomic number: It represents the number of protons in the nucleus of the atom. The higher this number, the heavier the element.
- Atomic mass: This number indicates the average mass of the atoms of a given element in atomic mass units (amu).
- Colors: In some tables, elements are drawn in different colors to indicate whether they are solids, liquids, or gases at room temperature.
New elements in the periodic table
In recent years, the periodic table has continued to grow with the addition of four new elements. These are located in period number 7 and are the Muscovy (Mc), the Tenesus (Ts), the Nihonium (Nh), and the Oganeson (Og). These elements were discovered by teams of scientists from Russia, Japan, and the United States, demonstrating the constant evolution and discovery in the field of chemistry. Studying the periodic table of elements is essential not only for those who study chemistry but for anyone interested in science. This table was created by the Russian chemist Dmitri Mendeleev, has allowed generations of scientists to advance in the knowledge of the materials that make up the universe. Today, knowledge of this not only allows us to identify elements, but also to anticipate their chemical and physical properties, making the periodic table a powerful tool in all branches of science.