Edexcel IGCSE Chemistry 复习笔记 1.6 5 Ionic compounds: Bonds, Structure & Properties

• The positive and negative charges are held together by the strong electrostatic forces of attraction between oppositely charged ions
• This is what holds ionic compounds together

Electrostatic forces hold the ions together in sodium chloride

• Ionic compounds are made of charged particles called ions which form a giant lattice structure
• Ionic substances have high melting and boiling points due to the presence of strong electrostatic forces acting between the oppositely charged ions
• These forces act in all directions and a lot of energy is required to overcome them

Strong electrostatic forces act in all directions in an ionic solid such as sodium chloride

• Ionic compounds are usually solid at room temperature and are non-volatile
• They are usually water soluble as both ionic compounds and water are polar  substances

Ionic compounds are soluble in water because the ions are easily hydrated by polar water molecules

• For electrical current to flow there must be present freely moving charged particles such as electrons or ions
• Ionic compounds can conduct electricity in the molten state or in solution as they have ions that can move and carry charge
• They cannot conduct electricity in the solid state as the ions are in fixed positions within the lattice and are unable to move