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Hydrogen Is seen to have 1 electron in the Is level, and to the right, helium, in Group 18, has 2 electrons in the Is level, a completely filled shell, the “duet rule. ” Helium is the first in the series of “noble gases. Moving down to period 2, lithium is the first element in the row, with a filled Is configuration (denoted by the [He] prior to the ass notation). The [He] is carried across the period as first the as and then the up orbital’s fill, arriving at the configuration for neon, following the “octet rule”. Period 3 follows a similar pattern. Please note that the number of outer-shell electrons, which is presented as the relights digit In the group number, Is the major determinant of the elements valence, thus, this Is the valence orbital. Towpaths. Boundless. Mom/ chemistry/periodic-properties/the-history-of-the-periodic-table/periodic-table- position-and-electron-configuration/The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behavior of the elements as their atomic number Increases: a new row Is begun when chemical behavior begins to repeat, meaning that elements with similar behavior fall into the same vertical columns. 1 OFF columns) by the number of electrons in the outer electron field. So An in IGRP. I has only 1 outer electron, whereas CLC in IGRP. VII has 7. From left to right are periods of increasing atomic number.
The groups are very important for understanding how any element will behave. The elements in each group share similar characteristics because they have the same number of outer electrons, so react similarly. Despite this, the reaction rate varies as you go down the periods because the distance between the outside electrons and the atom nucleus gets greater. Acid-Base Properties of Oxides Those oxides that are produced in the reactions above have various physical properties. Sodium and magnesium oxides have ionic structures and silicon, phosphorous and sulfur oxides have covalent bonding.
Aluminum oxide on the other hand, has a type of boding that is somewhere in between. Since aluminum has a very high charge density it is able to distort the electron cloud so that aluminum oxide has a very covalent character. In the table below are the reactions of period 3 oxides with water, with the resulting pH. You will notice that the trend in the pH of the solutions formed goes from alkaline to acidic. This is because the less electronegative sodium has a weak An-O bond and the oxygen is more easily given up to reacts with H+.
Further along though, a strong S-O bond keeps this together and more H+ is generated. The empathetic aluminum oxide has a bonding which is both ionic and covalent in nature. When these oxides are reacted with acids or bases, a naturalization would occur with a salt and water produced. Aluminum oxide is empathetic, meaning it reacts with both acids and bases. Http://science. Co. UK/ chemistry/inorganic/eatable. HTML Metallic character “Tendency of an atom to form costive ions by losing electrons is called its metallic character. ” The more readily an atom loses electrons, the more metallic it is.
The metallic character of elements decreases as we move across a row from left to right in the periodic table and increases as we move down a column in the periodic table. This is because on moving across a row in the periodic table, the number of valence electrons increases which causes elements to gain electrons rather than losing them. When we move down a column in the periodic table, the metallic character increases because the umber of valence electrons remains same and the atomic size increases which makes the valence electrons more far away from the nuclear attraction and thus easier to lose.