GCSE Chemistry - Formation of Ions #13

Summary

This video delves into the formation of ions, explaining that they are charged particles formed when atoms gain or lose electrons to achieve a stable, full outer shell. It highlights that elements in groups one, two, six, and seven readily form ions due to the minimal energy required to reach stability by losing or gaining one or two electrons. In contrast, elements in groups three, four, and five are less likely to form ions as it would require a significant energy expenditure to lose or gain three or four electrons. The video also demonstrates how to write equations representing the electron gain or loss during ion formation.

Takeaways

• 🔬 Ions are charged particles, which can be single atoms or groups of atoms.
• ⚛️ Atoms form ions by gaining or losing electrons to achieve a stable, full outer electron shell.
• 📊 The periodic table's group number indicates the number of valence electrons in an atom's outermost shell.
• 🔝 Alkaline metals (Group 1) easily lose one electron to form a +1 ion due to low energy requirement.
• 🔝 Alkaline earth metals (Group 2) can easily lose two electrons to form a +2 ion.
• 🔝 Group 6 elements tend to gain two electrons to form a -2 ion, while Group 7 elements gain one electron to form a -1 ion.
• 🚫 Elements in Groups 3, 4, and 5 are less likely to form ions as they would need to lose or gain multiple electrons, requiring more energy.
• ✏️ Chemical equations can represent the transfer of electrons between atoms, showing the formation of ions.
• 🔄 When atoms lose electrons, they form positive ions, and when they gain electrons, they form negative ions.
• 🔋 The energy required to lose or gain electrons influences the likelihood of an atom forming ions.

Q & A

What is an ion?

An ion is a charged particle, which can either be a single atom like Na+ or a group of atoms such as OH− (hydroxide ion).

How are ions formed?

Ions are formed when atoms gain or lose electrons in order to achieve a full outer electron shell, making them more stable.

What does the group number on the periodic table tell us?

The group number on the periodic table indicates how many electrons are in the outermost shell of the atoms in that group.

Why are group 1 elements more likely to form ions?

Group 1 elements only have to lose one electron to achieve a full outer shell, which requires little energy, making it easier for them to form ions.

Why do group 2 elements form 2+ ions?

Group 2 elements have two electrons in their outermost shell, which they can easily lose to form 2+ ions and become more stable.

Why don't we often see ions formed from elements in groups 3, 4, and 5?

Elements in groups 3, 4, and 5 would need to lose or gain three or four electrons, which requires a large amount of energy, so they are less likely to form ions.

What is the difference between how positive and negative ions are formed?

Positive ions are formed when atoms lose electrons, while negative ions are formed when atoms gain electrons.

How do we write chemical equations for ion formation?

For positive ions, the electron is placed on the right of the equation, indicating it is lost. For negative ions, the electron is placed on the left, indicating it is gained by the atom.

What is the chemical equation for sodium ion formation?

The equation for sodium ion formation is Na → Na+ + e−, where a sodium atom loses one electron to form a Na+ ion.

How would you write the equation for the formation of an oxygen ion?

The equation for oxygen ion formation is O + 2e− → O2−, where an oxygen atom gains two electrons to form an O2− ion.