main group element

Examples of main group element in the following topics:

• The Expanded Octet

  • Main group elements in the third period and below form compounds that deviate from the octet rule by having more than 8 valence electrons.
  • A hypervalent molecule is a molecule that contains one or more main group elements that bear more than eight electrons in their valence levels as a result of bonding.
  • For the elements in the second period of the periodic table (principal energy level n=2), the s2p6 electrons comprise the octet, and no d sublevel exists.
  • As a result, the second period elements (more specifically, the nonmetals C, N, O, F) obey the octet rule without exceptions.
  • However, some of the third-period elements (Si, P, S, and Cl) have been observed to bond to more than four other atoms, and thus need to involve more than the four pairs of electrons available in an s2p6 octet.

• Oxidation Numbers of Metals in Coordination Compounds

  • Transition metals are the elements in Groups 3 to 12 representing the d block of the periodic table.
  • The oxidation number is placed in parentheses after the name of the element (iron(III)).
  • However, it decreases in the latter elements.
  • Main-group elements, those in Groups 13 to 17, also exhibit multiple oxidation states.
  • The "common" oxidation states of these elements typically differ by two.

• Lanthanides and Actinides

  • The lanthanides and actinides form a group that appears almost disconnected from the rest of the periodic table.
  • This is due to the proper numerical position between Groups 2 and 3 of the transition metals.
  • The 14 elements (numbers 58 to 71) of the lanthanide series are also known as the rare earth elements.
  • The chemistry of the lanthanides differs from main group elements and transition metals because of the nature of the 4f orbitals.
  • The red highlighted group shows the lanthanide series and the blue highlighted group shows the actinide series.

• Variation of Physical Properties Within a Group

  • The physical properties (notably, melting and boiling points) of the elements in a given group vary as you move down the table.
  • In chemistry, a group is a vertical column in the periodic table of the chemical elements.
  • There are 18 groups in the standard periodic table, including the d-block elements but excluding the f-block elements.
  • Within a group of the periodic table, each element has the same valence electron configuration.
  • In the main group elements, the boron and carbon families (Groups 13 and 14) decrease in their boiling and melting points as you move down the group, whereas the nitrogen, oxygen, and fluorine families (Groups 15, 16, and 17) tend to increase in both.

• Electron Configurations and Magnetic Properties of Ions

  • The periodic table does more than just list the elements.
  • These elements comprise the s block of the periodic table.
  • The s and p blocks make up the main-group elements, also known as representative elements.
  • Elements in the same group or family have the same configuration of valence electrons, so they behave in chemically similar ways.
  • The magnetic properties of a given element depend on the electron configuration of that element, which will change when the element loses or gains an electron to form an ion.

• Transition Metals

  • The d-block elements are commonly known as transition metals or transition elements.
  • The transition metals are also known as thetransition elements or the d-block elements.
  • Transition metals can be said to possess the following characteristics generally not found in the main grouping of the periodic table.
  • A few compounds of main group elements are also paramagnetic (e.g., nitric oxide, oxygen).
  • The d-block is composed of groups 3 - 12 and periods 4 - 7.

• General Trends in Chemical Properties

  • The main body of the table is an 18 by 7 grid, and elements with the same number of valence electrons are kept together in groups (columns), such as the halogens and the noble gases.
  • The f block is usually included below the main table rather than within it to minimize the table's width.
  • Elements in the same group show patterns in atomic radius, ionization energy, and electronegativity.
  • From top to bottom in a group, the atomic radii of the elements increase: since there are more filled energy levels, valence electrons are found farther from the nucleus.
  • The number of valence shell electrons determines the family, or group, to which the element belongs.

• Periodic Table Position and Electron Configuration

  • The main body of the table is a 18 × 7 grid.
  • Elements with the same number of valence electrons are kept together in groups, such as the halogens and the noble gases.
  • The f-block is usually not included in the main table, but rather is floated below, as an inline f-block would often make the table impractically wide.
  • The elements in this table are laid out in the standard configuration of periods and groups.
  • Use the periodic table to identify atom properties such as groups and electron configurations.

• The Periodic Table

  • Each row of the periodic table is called a period and each column of the periodic table is called a group (or family).
  • Some groups have specific names like the halogens or noble gases.
  • Elements within the same period or group have similar properties.
  • An element's location in the periodic table is largely dependent on its electrons; the number of valence shell electrons determines its group, and the type of orbital in which the valence electrons lie in determines the element's block.
  • The atoms are grouped in order of increasing atomic number.

• Periodic Trends in Metallic Properties

  • Each of the columns of the periodic table is called a group.
  • Chemists have long found it convenient to refer to the elements of different groups, and in some cases of spans of groups, by the names shown in the table.
  • Keep in mind that group names can give clues about the elements' metallic properties.
  • So, the metallic properties of elements tends to decrease across a period and increase down a group.
  • Families of the periodic table are often grouped by metallic properties.