Arrangement of the Elements in groups in the periodic Table

Arrangement of the Elements in groups in the Periodic Table - Inorganic Chemistry

ChemistryExplain provides notes about Atomic Structure “Arrangement of the Elements in groups in the periodic Table” Inorganic chemistry jobs, Inorganic Chemistry, Inorganic chemistry examples.

Periodic Table

The chemical properties of an element are largely governed by the number of electrons in the outer shell, and their arrangement. If the elements are arranged in groups which have the same outer electronic arrangement, then elements within a group should show · similarities in chemical ·· and physical properties. One great advantage of this is that initially, it is only necessary to learn the properties of each group rather than the properties of each individual element.
Elements with one electron in their outer shell are called Group I (the alkali metals) and elements with two s electrons in their outer shell are called Group II (the alkaline earth metals). These two groups are known as the s-block elements because their properties result from the presence of s electrons.
Elements with three electrons in their outer shell (two s electrons and one p electron) are called Group III, and similarly, Group IV elements have four outer electrons, Group V elements have five outer electrons, Group VI elements have six outer electrons and Group VII elements have seven outer electrons; Group 0 elements have a full outer shell of electrons so that the next shell is empty; hence the group name. Groups III, IV, V, VI, VII, and 0 all have p orbitals filled and because their properties are dependent on the · presence of p electrons, they are called jointly the p-block elements.
For More Chegg Questions

• Inorganic Chemistry
• Organic Chemistry
• Physical Chemistry

In a similar way, elements, where d orbitals are being filled, are called the d-block, or transition elements. In these, d electrons are being added to the penultimate shell. · · Finally, elements, where f orbitals are filling, are called the /-block, and here the f electrons are entering the antepenultimate (or second from the outside) shell. In the periodic tab!~ (Table 1.4), the elements are arranged in order of increasing atomic number, which is in order of increased nuclear charge, or increased number of orbital electrons. Thus each element contains one more orbital electron than the preceding element. Instead of listing the 103 elements as one long list, the periodic table arranges them into several horizontal rows or periods, in such a way that each row begins with an alkali metal and ends with a noble gas. The sequence in which the various energy levels are filled determines the number of elements in each period, and the periodic table can be divided into four main regions according to whether the s, p, d, or f levels are bein~ filled.

For More Chemistry Notes and Helpful Content Subscribe Our YouTube Chanel - ChemistryExplain
The alkali metals appear in a vertical column labeled Group I, in which all elements have one electron in their outer shell, and hence have similar properties. Thus w~en one element in a group reacts with a reagent, the other elements in the group will probably react similarly, forming compounds that have similar formulae. Thus reactions of new compounds and their formulae may be predicted by analogy with known compounds. Similarly, the noble gases all appear in a vertical column labeled Group 0, and all have a complete outer shell of electrons. This is called the long form of the periodic table. It has many advantages, the most important being that it emphasizes the similarity of properties within a group and the relation between the group and the electron structure. The d-block elements are referred to as the transition elements as they are situated between the s- and p-blocks.
Hydrogen and helium differ from the rest of the elements because there are no p orbitals in the first shell. Helium obviously belongs to Group 0, the noble gases, which are chemically inactive because their outer shell of electrons is full. Hydrogen is more difficult to place in a group. It could be included in Group I because it has one electron in its outer shell, is univalent, and commonly forms univalent positive ions .. However, hydrogen is not a metal and is a gas whilst Li, Na, K, Rb, and Cs are metals and are solids. Similarly, hydrogen could be included in Group VII because it is one electron short of a complete shell, or in Group IV because its outer shell is half full. Hydrogen does not resemble the alkali metals, the halogens, or Group IV very closely. Hydrogen atoms are extremely small and have many unique properties. Thus there is a case for placing hydrogen in a group on its own.