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Grade 7Periodic tableTrends in the Periodic Table


Metallic and non-metallic character


In the periodic table, elements are classified according to their properties. One main classification is based on whether the elements are metals or nonmetals. This understanding is very important to understand the nature and behavior of different elements.

Periodic table overview

Hydrogen Helium Took Happen B C N Hey

The periodic table is arranged in a grid format, where the elements are arranged in rows called periods and columns called groups. Moving forward in a period, we find different types of elements ranging from metals to non-metals.

Metal character

Metallic character indicates the level of reactivity of the metal. Metals tend to lose electrons and form positive ions or cations. This tendency increases for elements with more metallic character.

Movements in the periodic table

Let us see how the character of metal changes as we move:

  • In a period: Metallic character decreases as we move from left to right in a period. Elements on the left are metals and are more likely to lose electrons.
  • Down the group: As we move down the group, metallic character increases. As the number of electron shells away from the nucleus increases, it becomes easier for these elements to lose electrons.
Metal Character Duration

Examples of metals

Metals include the following elements:

  • Na (sodium)
  • Mg (Magnesium)
  • Al (Aluminum)

These elements usually form positive ions, such as:

Na → Na + + e -

Non-metallic character

Nonmetallic character refers to the tendency of an element to gain electrons and form negative ions or anions. Nonmetals are mainly located on the right side of the periodic table.

Movements in the periodic table

Let us see how the nonmetallic character differs:

  • In a period: From left to right, non-metallic character increases. Non-metals are more likely to gain electrons to form negative ions.
  • Going down the group: Nonmetallic character decreases down the group because electron attraction becomes less favourable due to addition of more electron shells.
Non-metallic character Duration

Examples of nonmetals

Some common nonmetals are:

  • Cl (Chlorine)
  • O (oxygen)
  • N (Nitrogen)

These elements form negative ions, such as:

Cl + e - → Cl -

Importance of metallic and non-metallic characters

Understanding these characteristics helps predict the behavior of elements in chemical reactions. Metals are generally good conductors of electricity and heat, while nonmetals are good insulators.

Let's consider some scenarios:

  • Electrical conductivity: Metals like Cu are used for electrical wires because they have excellent ability to conduct electricity.
  • Reactivity: Elements with high metallic character form basic oxides, whereas elements with high non-metallic character form acidic oxides.

Overall, analysis of trends in metallic and nonmetallic character in the periodic table provides a fundamental understanding of the interactions of elements in various scientific and industrial processes.


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