Periodic table can be defined as "a representation of certain data in a systematic way in which the data in vertical columns and the data in horizontal lines show some gradation and periodic connection."
Four new elements has been added to the periodic table which hold the atomic number 113, 115, 117 and 118. These elements yet to be named and as of now they are nicknamed as Uut, Uup, Uus and Uuo respectively. These elements occupy the 7th row of the periodic table. The 7th row of the periodic table takes completion by the addition of these four elements.
The International Union of Pure and Applied Chemistry (IUPAC) has declared officially the addition of 4 new elements in the modern periodic table at the end of 2015. The 4 new elements are highly unstable and does not exist in nature. They are radioactive and man made. These element can be named in the coming months.however, they can be named after a scientist or mineral or place of the country.
- With the discovery of elements and the study of their properties a need was generated to organize the findings.
- Certain similarities in the properties of these elements, their compounds and their reactions made the scientists arrange them according to their properties.
- Initially the elements were divided as metals and non metals. With further development, further division took place as inert gases were classified in a different group.
- The law of triads and law of octaves were improvised attempts to classify and group different elements but even these could not satisfactorily classify the elements and the periodicity of the properties. The advent of the periodic table tried to explain these short comings.
The need to put together elements that show similar properties required some easy method which will explain the proper periodicity of the properties. Development of the periodic table addressed these to an extent.
The typical periodic table will have horizontal periods and vertical columns called groups. For increase in the atomic mass of the elements one has to follow the period in which the properties are not similar. The vertical groups refer to the elements with similar properties with increasing atomic masses from top to down.
In this periodic table the symbols of the elements are given with their atomic masses.
The periodic table which will give the information about the nature of ion formation of each element is called the periodic table with charges. Elements are divided in to those with electro positive and electronegative character.If an element loses one or more electrons to form an ion it is called electropositive element and its ions have positive charge.
If the element accepts one or more electrons to complete its orbit and become an ion they are called electronegative elements. Depending on the group it belongs to, an element will have one or more charges. Depending on the ease with which electron or electrons are donated or accepted and the subsequent stability of the ion while forming a compound makes even elements of the same group to have more than one type of charge.The periodic table which gives the information about these charges is called the periodic table with charges.
Electronegativity is a relative value based upon the ionization energy and electron affinity. Of the three proposed scales of measurement, the Pauling scale is generally taken as the measure of electronegativity. Accordingly hydrogen is given the electronegativity of 1 and fluorine the maximum value of 4.
All the other elements are compared with these values based on their re activities. The periodic table giving these values is known as the electronegativity periodic table
The properties that are periodic in nature in a periodic table have a pattern of trends both in a period while moving from left to right and in a group while moving from top to the bottom of the table. They can be given as
- Covalent Atomic radius: In a period from left to right the covalent radius of the atom reduces, while in a group from top to bottom it increases.
- For d-block elements the increase is very less in the period while Lanthanides show a special property called Lanthanide contraction.
- Ionization Energy: Along a period from left to right the ionization energy increases with slight variation when the ion obtained is stable in fully filled or half filled stability state. In a group it decreases as we proceed from the top to bottom.
- Electron affinity: With increase in atomic number in a period generally the electron affinity increases. In a group, while the atomic number increases, the electron affinity decreases.
- Electronegativity: Electronegativity increases across a particular period with increasing atomic number. The electronegativity decreases in a group from top to bottom in the periodic table.
In a periodic table the groups are the vertical columns. The first column from the left is called the alkali metal group. The second from left is known as alkaline earth metals. Elements in groups will have similar properties since they display similar outermost orbital configuration. Group 18 contains inert gases, and 17th group are halogens. Group 15 are the carbon group where the covalent compounds are predominant.
→ Read More
- Demitriv Mendeleev based his periodic table on the basis of increasing atomic masses.
- Mendeleev's periodic table is generally called as Periodic table with mass. His periodic table could not explain the presence of isotopes in their placement in periodic table.
- Modern periodic table which is based on atomic number relates to the electrons and protons. Isotopes do not come in to the picture since isotopes are formed from the differences in neutrons.
- Thus the modern periodic table with masses give the mass of the most stable and abundant isotopic mass of elements.
Group of elements which will show a lot of similarities of properties with reference to their compounds and reactions, are sometimes termed as belonging to one family. Thus family of alkali metals, halogen family, chalcogen family, inert element family and Lanthanide and actinide families are some of the periodic table families.
Metals on the periodic table are the s, d and f block elements. The elements on the left side of the periodic table are metals and the metallic character increases as one goes down the periodic table from top.
The p block elements also show increasingly metallic character towards the bottom elements in their groups and they are called metalloids.
Modern periodic table is the periodic table where the groups are divided into 18 groups apart from lanthanides and actinides. They are designated from 1 to 18 groups and not like the earlier IA, IB like grouping.
Periodic table facts are as follows:
- Mendeleev's periodic table is the first attempt to organize the elements in a periodic table.
- Modern periodic table is based on increasing atomic numbers. The group and the period an element belongs to gives the information of its last stable electron.
- Majority of elements in the periodic table are metals. Alkali metals, alkaline earth metals, basic metals transition metals, Lanthanide metals and actinide metals are the classes of metals.
- The naturally occurring elements in the periodic table are 90. Rest are man made elements. Technetium is the first man made element.
- The modern periodic table can accommodate 118 elements. So far 111 elements are discovered. researchers are working on an element with atomic number 120 which needs a modification in the periodic table.
- The present periodic table is approved latest in February 2010. IUPAC periodically renews the approval of the periodic table.
Periodic table list according to the increasing number of electrons.
|Boron ||B ||5 ||10.81 ||Chromium ||Cr ||24 ||52.00 ||Technetium ||Tc||43 ||98 |
|Carbon ||C ||6 ||12.01 ||Manganese ||Mn ||25 ||54.94 ||Ruthenium ||Ru ||44 ||101.1 |
|Nitrogen ||N ||7 ||14.01 ||Iron ||Fe ||26 ||55.85 ||Rhodium ||Rh ||45 ||102.9 |
|Oxygen ||O ||8 ||16.00 ||Cobalt ||Co ||27 ||58.93 ||Palladium ||Pd ||46 ||106.4 |
|Fluorine ||F ||9 ||19.00 ||Nickel ||Ni ||28 ||58.70 ||Silver ||Ag ||47 ||107.9 |
|Neon ||Ne ||10 ||20.18 ||Copper ||Cu ||29 ||63.55 ||Cadmium ||Cd ||48 ||112.4 |
|Sodium ||Na ||11 ||22.99 ||Zinc ||Zn ||30 ||6541 ||Indium ||In ||49 ||114.8 |
|Magnesium ||Mg ||12 ||24.31 ||Gallium ||Ga ||31 ||69.72 ||Tin ||Sn ||50 ||118.7 |
|Aluminium ||Al ||13 ||26.98 ||Germanium ||Ge ||32 ||72.61 ||Antimony ||Sb ||51 ||121.8 |
|Silicon ||Si ||14 ||28.09 ||Arsenic ||Ar ||33 ||74.92 ||Tellurium ||Te ||52 ||127.6 |
|Phosphorous ||P ||15 ||30.97 ||Selenium ||Se ||34 ||78.96 ||Iodine ||I ||53 ||126.9 |
|Sulfur ||S ||16 ||32.07 ||Bromine ||Br ||35 ||79.9 ||Xenon ||Xe ||54 ||131.3 |
|Chlorine ||Cl ||17 ||35.45 ||Krypton ||Kr ||36 ||83.80 ||Cesium ||Cs ||55 ||132.9 |
|Argon ||Ar ||18 ||39.95 ||Rubidium ||Ru ||37 ||85.47 ||Barium ||Ba ||56 ||13703 |
|Potassium ||K ||19 ||39.10 ||Strontium ||Sr ||38 ||87.62 ||Lanthanum ||La ||57 ||138.9 |
|Promethium ||Pm ||61 ||145 ||Mercury ||Hg||80 ||200.6 ||Einstenium ||Es ||99 ||254 |
|Samarium ||Sm ||62 ||150.4 ||Thallium ||Tl ||81 ||204.4 ||Fermium ||Fm ||100 ||253 |
|Europium ||Eu ||63 ||152.0 ||Lead ||Pb ||82 ||207.2 ||Mendelevium||Md ||101 ||256 |
|Gadolinium ||Gd ||64 ||157.3 ||Bismuth ||Bi ||83 ||209 ||Nobelium ||No ||102 ||253 |
|Terbium ||Tb ||65 ||158.9 ||Polonium ||Po ||84 ||209 ||Lawrencium ||Lr ||103 ||257 |
|Dysporsium ||Dy ||66 ||162.5 ||Astatine ||At ||85 ||210 ||Rutherfordium ||Rf ||104 ||263 |
|Holmium ||Ho ||67 ||164.9 ||Radon ||Ru ||86 ||222 ||Dunium ||Db ||105 ||262 |
|Erbium ||Er ||68 ||167.3 ||Francium ||Fr ||87 ||223 ||Seaborgium ||Sg ||106 ||266 |
|Thulium ||Tm ||69 ||168.9 ||Radium ||Ra ||88 ||226 ||Bohrium ||Bh ||107 ||267 |
|Ytterbium ||Yb ||70 ||173.0 ||Actinium ||Ac ||89 ||227 ||Hassium ||Hs ||108 ||277|
|Lutetium ||Lu ||71 ||175.0 ||Thorium ||Th ||90 ||232 ||Meitnerium ||Mt ||109 ||268 |
|Hafnium ||Hf ||72 ||178.5 ||Protactinium ||Pa ||91 ||231 ||Darmstadium ||Ds ||110 ||281 |
|Tantalum ||Ta ||73 ||180.9 ||Uranium ||U ||92 ||238 ||Roentgenium ||Rg ||111 ||272 |
|Tungsten ||W ||74 ||183.9 ||Neptunium ||Np ||93 ||244 || || || || |
|Rhenium ||Re ||75 ||186.2 ||Plutonium ||Pu ||94 ||242 || || || || |
|Osmium ||Os ||76 ||190.2 ||Americium ||Am ||95 ||243 || || || || |
Periodic table contains the following parts.
- Alkali metals
- Alkali Earth metals
- Transition metals
- Non metals
- Nobel gases
- Lanthanide elements
- Actinide elements
The first periodic table is designed by Dimitrev Mendeleev basing atomic weights as the criteria.
Mendeleev's Periodic table
The properties of the elements give an idea of the group properties of the periodic table. Some of the properties are
- Group 1: elements are mono valent and electropositive elements.
- Group 2: elements are bi valent and are metallic in nature. Their oxides are basic.
- Group 13: elements are also electro positive and trivalent.
- Group 14: elements form covalent bonds. Their valencies are either 2 or 4.
- Group 15: elements are electonegative and are trivalent anionic non metals and metalloids.
- Group 16: are electronegative bivalent non metals.
- Group 17: are monovalent highly electronegative elements of their respective periods.
- Group 18: elements are inert in nature.
Transition elements exhibit variable valencies. In any given period, atomic size reduces from left to right.
Advanced periodic table is the one which gives all possible information like the physical properties, chemical properties, types of bonds and compounds that can be formed, nature of the elements, electronic configuration etc.