{"id":47,"date":"2020-08-21T18:07:21","date_gmt":"2020-08-21T18:07:21","guid":{"rendered":"http:\/\/blogs.harvard.edu\/chemist\/?p=47"},"modified":"2020-09-19T22:44:35","modified_gmt":"2020-09-19T22:44:35","slug":"limitations-of-mendeleevs-periodic-table","status":"publish","type":"post","link":"https:\/\/archive.blogs.harvard.edu\/chemist\/limitations-of-mendeleevs-periodic-table\/","title":{"rendered":"Limitations Of Mendeleev&#8217;s Periodic Table"},"content":{"rendered":"<p><span style=\"font-family: georgia, palatino, serif;font-size: 12pt\">Mendeleev&#8217;s Periodic Table in spite of its advantages suffers from the following drawbacks and has thus limitations in its application:<\/span><\/p>\n<p><span style=\"font-family: georgia, palatino, serif;font-size: 12pt\">Position of hydrogen is not clear because it resembles with both alkali metals and halogens. It gives the positive H+ ions like alkali metals and gives the hydride ions like halides.<\/span><\/p>\n<p><span style=\"font-family: georgia, palatino, serif;font-size: 12pt\">Certain chemically similar elements, e.g., copper, gold, platinum are placed in different groups while some dissimilar elements are grouped together.<\/span><\/p>\n<p><span style=\"font-family: georgia, palatino, serif;font-size: 12pt\">Certain elements of higher atomic weight precede others with lower atomic weight. Argon (At. Wt. = 40) Precedes Potassium (At. Wt. = 39) Cobalt (At. Wt. = 59) Precedes Nickel (At. Wt. = 58.6)<\/span><\/p>\n<p><span style=\"font-family: georgia, palatino, serif;font-size: 12pt\">No position is assigned to isotopes in different groups.<\/span><\/p>\n<p><span style=\"font-family: georgia, palatino, serif;font-size: 12pt\">Maximum valence state is depicted by an element in a particular group. The elements of group VIII usually do not depict 8 maximum oxidation state except ruthenium and osmium.<\/span><\/p>\n<p><span style=\"font-family: georgia, palatino, serif;font-size: 12pt\">No explanation is available for the inert pair effect and stability of valence states differing by units of two.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Mendeleev&#8217;s Periodic Table in spite of its advantages suffers from the following drawbacks and has thus limitations in its application: Position of hydrogen is not clear because it resembles with both alkali metals and halogens. It gives the positive H+ ions like alkali metals and gives the hydride ions like halides. Certain chemically similar elements, [&hellip;]<\/p>\n","protected":false},"author":9844,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[283878],"tags":[],"class_list":["post-47","post","type-post","status-publish","format-standard","hentry","category-general-chemistry"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/posts\/47","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/users\/9844"}],"replies":[{"embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/comments?post=47"}],"version-history":[{"count":2,"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/posts\/47\/revisions"}],"predecessor-version":[{"id":49,"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/posts\/47\/revisions\/49"}],"wp:attachment":[{"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/media?parent=47"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/categories?post=47"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/chemist\/wp-json\/wp\/v2\/tags?post=47"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}