(40) GCSE Chemistry Revision "Metals"

The Periodic Table and Elements

• Position of Elements

  • Most elements are metals, located on the left and center of the periodic table.

  • Non-metals are found on the right-hand side.

Classification of Metals

• Categories

  • Highly reactive metals in Group 1 (Alkali metals) and Group 2 (Alkaline earth metals).

  • Transition metals located in the center are generally less reactive.

Noble Gases and Reactivity

• Group 0 Elements

  • Noble gases possess a full outer energy level, making them stable and unreactive.

Metal Reactivity and Ions

• Metals react by losing electrons to achieve a full outer energy level, similar to noble gases.

• Example Elements:

  • Lithium (Group 1):

    • 3 protons, 3 electrons; loses 1 electron to become a lithium ion (Li⁺).

    • Achieves the electron configuration of helium.

  • Sodium (Group 1):

    • 11 protons, 11 electrons; loses 1 electron to become a sodium ion (Na⁺)

    • Now has the electron configuration of neon.

  • Aluminium (Group 3):

    • 13 protons, 13 electrons; loses 3 electrons to form an aluminium ion (Al³⁺).

    • Achieves a full outer level.

Formation of Positive Ions

• Understanding Charges

  • Atoms have an equal number of protons and electrons, resulting in a net charge of zero.

  • Losing electrons leads to an overall positive charge, hence forming an ion.

  • Example of Lithium Ion:

    • Loses 1 electron: 3 protons, 2 electrons = Li⁺ (charge +1).

Practice and Examples

• Sodium Ion:

  • Formed by losing 1 outer electron: Na has 11 protons and 10 electrons = Na⁺ (charge +1).

• Barium Ion:

  • Barium (Group 2) loses 2 electrons: 4 protons, 2 electrons = Ba²⁺ (charge +2).

Conclusion

• Metals consistently form positive ions when they react by losing outer electrons to secure a full outer energy level.