I’ll keep this very short and to the point. I have explained the concept of valence electrons for d block and f block elements in separate articles “d block elements” and “f block elements.” (Because it is little bit different and first you need to know about the concept of orbitals) Trends in periodic table (Periodic trends)
Group 18 indicates 8 valence electrons, not 18. Group 17 indicates 7 valence electrons, not 17. Group 16 indicates 6 valence electrons, not 16. Group 15 indicates 5 valence electrons, not 15. Group 14 indicates 4 valence electrons, not 14. Group 13 indicates 3 valence electrons, not 13. Thus, the arrangement of electrons in the orbit of Chlorine atom is as shown above. (In other words, Chlorine has total 17 electrons).Īnd now you know very well that 2nd orbit holds maximum 8 electrons. List of group 18 elements with their symbol are given below: Element name Symbol Neon Ne Argon Ar Krypton Kr Xenon Xe Radon Rn Oganesson OgĪlso read: Why are these elements known as p-block elements?Ītomic number of chlorine is 17. List of group 17 elements with their symbol are given below: Element name Symbol Fluorine F Chlorine Cl Bromine Br Iodine I Astatine At Tennessine Ts List of group 16 elements with their symbol are given below: Element name Symbol Oxygen O Sulphur S Selenium Se Tellurium Te Polonium Po Livermorium Lv List of group 15 elements with their symbol are given below: Element name Symbol Nitrogen N Phosphorus P Arsenic As Antimony Sb Bismuth Bi Moscovium Mc List of group 14 elements with their symbol are given below: Element name Symbol Carbon C Silicon Si Germanium Ge Tin Sn Led Pb Flerovium Fl List of group 13 elements with their symbol are given below: Element name Symbol Boron B Aluminum Al Gallium Ga Indium In Thallium Tl Nihonium Nh The following groups are included in the p block of periodic table. Now, here is your p block on the Periodic table. Here, you will exactly come to know how Henry Moseley arranged the elements in periodic table on the basis of modern periodic law. How are elements arranged in periodic table?
Modern periodic law says that the properties of elements are the Periodic function of their atomic number.Īccording to the modern periodic law given by Henry Moseley, the elements should be arranged in the table on the basis of their ATOMIC NUMBER.Īfter arranging all the elements based on atomic number, the modern periodic table came into existence.Mandeleev law says that the properties of elements are the functions of their atomic mass.Henry Moseley arranged the elements according to the increasing atomic number.Mendeleev arranged the elements according to the increasing atomic mass.
This law is exactly similar to the Mendeleev law, but the only difference is Modern Periodic Law was given by Henry Moseley in 1913. The properties of the elements are the Periodic function of their ATOMIC NUMBERS. Yes, all the elements in modern periodic table are arranged on the basis of their ATOMIC NUMBER. We have seen in previous section that Dobereiner’s law, Newland’s law as well as Mendeleev law were based on the arrangements of elements according to their increasing atomic masses.īut the only difference in modern periodic law is I have also discussed the merits and demerits of the Mendeleev periodic table. I know this seems a little difficult for you, so you can refer to this detailed guide on “ Mendeleev periodic table” where I have explained all these things with proper images for your better understanding. So there were some empty blocks seen on the Mendeleev periodic table. Now look, while arranging the elements according to atomic masses, Mendeleev found that the properties of few elements were not matching with any of the previous ones, so he didn’t place such elements in that particular column. Why are some blocks empty in the above Mendeleev periodic table? That’s why Mendeleev placed those elements in the same block. The short answer: Those elements show similarly in their properties. Have you noticed that many blocks have more than one element in Mendeleev periodic table? Why? There are a total 8 vertical columns in the Mendeleev periodic table, which are known as groups.Īnd there are 7 horizontal rows, which are known as periods. This table is known as the Mendeleev periodic table of elements.