Updated: Oct 2, 2020
Elements are the first stops from where the Journey of Chemistry starts and their compounds make this journey colorful and joyful with their utilization.
The beauty of CHEMISTRY lies in the colors of elements and How they change their original color when they transfer from one form to another through a series of chemical reactions. Due to this, CHEMICAL SCIENCE is the WORLD OF CURIOSITIES from many generations.
The Periodic Table is a way of listing the elements. Elements are listed in the table by the structure of their atoms. It is called "periodic" because elements are lined up in periods. This includes how many protons they have as well as how many electrons they have in their outer shell. From left to right and top to bottom, the elements are listed in the order of their atomic number, which is the number of protons in each atom.
Important Points to know Before studying Periodic Table
Who invented the periodic table?
The periodic table was proposed by Russian chemist Dmitri Mendeleev in 1869.
How periodic table works?
The periodic table works by categorizing the elements in periods and groups.
What is period?
Each horizontal row in the table is a period. There are seven periods. The first one is short and only has two elements, hydrogen and helium. The remaining periods go on increasing from left to right with increasing atomic number of elements.
What is Group?
Groups are the columns of the periodic table. There are 18 columns or groups and different groups have different properties.
Group 1 : Alkali Metals.
Group 2: Alkaline Earth Metals.
Group 3 to 12: Transition Metals.
Group 13 to 16: Post transition Metals, Metalloids and Non Metals.
Group 17 : Halogens.
Group 18 : Noble gases
This lining-up and grouping of similar elements helps chemists when working with elements. They can understand and predict how an element might react or behave in a certain situation.
What are Element Abbreviations?
Each element has its own name and abbreviation (Short name) in the periodic table.
Role of some important terms in the study of Periodic Table:
Appearance: helps to study the existence of element based on the morphological appearance.
Phase: helps to study existence of element and its form around us.
Block: helps to study different regions of the periodic table based on the outer shell of electrons within the elements atoms.
Group: helps to study a family of elements which have the same number of valence electrons and similar chemical properties.
Period: helps to study that all of the elements in a period have the same number of atomic orbitals which is the number of that period. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.
Series: helps to study elements by categorizing them as per their chemical behavior .
Atomic number: helps to identify the element of an atom. also the modern periodic table is organized according to increasing atomic number hence it is the key factor in determining the properties of an element
Atomic weight: helps to study the average of the mass of all the atoms of all the isotopes of an element, based on the abundance of isotopes.
Number of Electron, Proton and Neutron: Atoms are made of extremely tiny particles called protons, neutrons, and electrons. Protons and neutrons are in the center of the atom, making up the nucleus. Proton—positive; electron—negative; neutron—no charge. The charge on the proton and electron are exactly the same size but opposite. The same number of protons and
electrons exactly cancel one another in a neutral atom. Neutrons are responsible for the number of Isotope of atom of an element as proton and neutron together form atomic weight of an atom Even though the number of proton is constant for the atom but number of neutrons can be different and hence difference in atomic weight occurs which leads to form different isotopes of atom of an element.
Distribution of electron: helps to study The arrangement of Electrons in Different Orbits. There are Four shell namely K, L, M, N which are occupied by electrons depending on their limits. K denotes the first shell (or energy level), L the second shell, M, the third shell, and so on. In other words, the K, L, M, N notation only indicates the number of electrons an atom has with each principal quantum number (n). Each shell can contain only a fixed number of electrons. The first shell (K) can hold up to 2 electrons, the second shell (L) can hold up to eight (2 + 6) electrons, the third shell (M) can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the (N) shell can in principle hold up to 2(n2) electrons. The outermost shell will have maximum energy. Now it is important to understand the distribution and arrangement of electrons in the atoms of any elements in the different energy levels. An atom of any element is most stable when it has minimum energy.
Isotopes: helps to study the existence of stable and unstable forms of atom of an element that have the same quantity of protons but differ in the number of neutrons they possess and hence differ in their atomic weight.
Electronic configuration: helps to determine the valence electrons on an atom. This is important because valence electrons contribute to the unique reactivity of each atom.
Valency: Valence electrons are the electrons that are present in the
outermost electron shell of an atom in the highest energy level. They are important to an atom because the fewer valence electrons that the atom holds, the less stable it becomes and thus increases the reactivity of the atom to participate in reactions.
Atomicity: Atomicity indicates the number of atoms present in a single molecule of an element, substance or compound.
Melting point: The melting point is the amount of energy required to break a bond(s) to change the solid phase of a substance to a liquid. Generally, the stronger the bond between the atoms of an element, the more energy required to break that bond. As the atomic number of elements increases, the melting point increases because there are more electrons around the nucleus, which creates a stronger negatively-charged force. With stronger forces, the melting point rises.The melting point of a molecule or compound is a very important characteristic.
Boiling point: From the top to the bottom of the periodic table, there observes a rough correlation between the atomic mass of elements and their boiling points. Lighter elements such as hydrogen and helium tend to have very low boiling points, and elements with greater atomic mass boil at higher temperatures. The boiling point of organic compounds can give important information about their physical properties and structural characteristics. Boiling point helps identify and characterize a compound. A liquid at a higher pressure has a higher boiling point than when that liquid is at lower atmospheric pressure.
Density: Density is important because it affects whether objects will float or sink. It is an important property to consider when preparing things or compounds in chemistry to understand their applications. Density is the mass of a substance per unit of volume. It is used to measure the compactness of a substance, and is commonly expressed in g/cm³, or lb/ft³. The density of a sample is expressed with the Greek letter "ρ" (the Latin letter D can also be used) and is calculated as:
ρ = m / v.
Critical temperature: Gases can be converted to liquids by compressing the gas at a suitable temperature. The critical temperature of a substance is the temperature at and above which vapor of the substance cannot be liquefied, no matter how much pressure is applied. Every substance has a critical temperature.
Thermal conductivity: Thermal conductivity results from the transfer of kinetic energy under the influence of a pressure called heat. Thermal conductivity λ is defined as ability of material to transmit heat and it is measured in watts per square metre of surface area for a temperature gradient of 1 K per unit thickness of 1 m.
Electrical type: Element is the combination of particles (protons and neutrons) with the electrons in their shell. Electrical conductivity is a feature of each element or molecules.
Electro-negativity: It is a chemical property that describes the tendency of an atom to attract a shared pair of electrons (or electron density) towards itself. An atom's electro-negativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. fluorine has the maximum elecro-negativity of 4 among all elements.