Electronic Configuration and the Periodic Table

Development of the Periodic Table The Modern Periodic Table 

Effective Nuclear Charge Periodic Trends in Properties of Elements 

Periodic Trends in Chemical Properties of the Main Group. Elements t  

Although some of their biochemical properties vary, the physical and chemical properties of the alkali metals are quite similar. This is why they were placed in the same group in the periodic table in the first place. It turns out they belong in the same group because they have the same valence electron configuration. 

At the end of this chapter, you will be able to answer a series of questions about the alkali metals and the ions that they form [ I Page 288]. 

In Chapter 2, you learned that the elements in the periodic table are arranged in order of increasing atomic number, but that doesn t explain the unusual shape of the table. The shape is determined by the sequence used to fill the subshells with electrons. In the following figure, the periodic table is divided into sections based on the type of subshell (s, p, d, or f) receiving the last electron in the building-up process. 

The periodic table divided into blocks of elements based on the type of subshell receiving the last electron in the building-up process. 

The valence electrons are the most chemically important electrons in an atom. They reside in the highest, occupied principal shell of an atom (largest n), and are the farthest away from the nucleus. They can also be described as the electrons outside the stable, filled inner core of electrons. Either way, the valence electrons determine the chemical properties of an element. 

The metals in Group IIA have two valence electrons, both in an s-subshell outside the stable noble gas core. It should not be surprising that each forms an ion with a 2+ charge, the result of losing both valence electrons. Be2+, Mg2+, and Ca2+ each have the stable electronic configuration of a noble gas. The l[Kr]3d °) configuration of the strontium ion, Srz+, with a completely tilled 3d-subshell outside the [Kr] noble gas core, is called a pseudo-noble gas core. Pseudo-noble gas cores are very stable, too. Don t be confused by this. Focus on the valence electrons, those in the highest occupied principal shell, the n = 5 shell in strontium. They are the chemically important electrons. 

Aluminum, a chemically reactive metal in Group IIIA, has three valence electrons and forms a very stable 3+ ion. The ten electrons that remain in the Al3+ ion have the neon configuration. The other metals in Group IIIA behave similarly. 

In This Chapter, You Will Learn some of the chemical and physical properties of the elements and how these properties are related to each element s position in the periodic table. 

In the nineteenth century, chemists had only a vague idea of atoms and molecules and did not yet know about electrons and protons. Nevertheless, they devised the periodic table using their knowledge of atomic masses. Accurate measurements of the atomic masses of many elements had already been made. Arranging elements according to their atomic masses in a periodic table seemed logical to those chemists, who believed that chemical behavior should somehow be related to atomic mass. 

In 1864 the English chemist John Newlands noticed that when the elements were arranged in order of atomic mass, every eighth element had similar properties. Newlands referred to this peculiar relationship as the law of octaves. However, this law turned out to be inadequate fra elements beyond calcium, and Newlands s work was not accepted by the scientific community. 

In 1869 the Russian chemist Dmitri Mendeleev and the German chemist Lothar Meyer independently proposed a much more extensive tabulation of the elements based on the regular, periodic recurrence of properties—a phenomenon known as periodicity. 

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Florida State University. Electron Configurations and the Periodic Table. Available online. URE http //winel.sb.fsu.edu/ chml045/notes/Struct/EPeriod/Struct09.htm. 

Inorganic and physical chemistry Atomic orbitals, electronic configurations and the Periodic Table 1... 

ATOMIC ORBITALS, ELECTRONIC CONFIGURATIONS AND THE PERIODIC TABLE 2... 

Electron Spin and the Pauli Exclusion Principle Orbital Energy Levels in Multielectron Atoms Electron Configurations of Multielectron Atoms Electron Configurations and the Periodic Table... 

The completely filled d sublevel and half-filled 4s sublevel is a very stable configuration. ELECTRON CONFIGURATIONS AND THE PERIODIC TABLE... 

There obviously is some relationship between the electronic configuration and the periodic table. 

Electron Configuration, and the Periodic Table Ionic bonding involves the complete transfer of electrons between two atoms of widely different electronegativities charged ions are formed (one positive from the loss of electrons and one negative from the gain of electrons), both of which usually have a stable octet outer shell. The ionic bond results from the attraction between the positive cation and negative anion. 

A. Covalent Bonding, Electron Configuration, and the Periodic Table Covalent bonds involve the sharing of electron pairs between atoms of... 

If you missed 31, go to Electronic Configuration and the Periodic Table, page 239. 

In this chapter we will learn to use electron configurations and the periodic table to predict the type of bond atoms will form, as well as the number of bonds an atom of a particular element can form and the stability of the product. 

Electron Configuration and the Periodic Table Strontium, which is used to produce red fireworks, has an electron configuration of [Kr]5s. Without using the periodic table, determine the group, period, and block of strontium. 

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