Types of Substance Flashcards
All 5 cards in this deck
What are the four types of substance that elements and compounds are classified into by structure and bonding?
Ionic, simple molecular (covalent), giant covalent and metallic.
Which types of substance conduct electricity when they are solid?
Metallic substances (graphite is the giant covalent exception).
How does solubility in water usually differ between ionic compounds and simple molecular substances?
Ionic compounds are usually soluble in water; simple molecular substances are usually insoluble.
True or false? All covalent substances have low melting points.
False. Simple molecular covalent substances do, but giant covalent substances such as diamond and silicon dioxide have very high melting points.
What are the steps to classify an unknown substance from its physical properties?
e.g. melting point 801 °C, soluble in water, conducts only when molten or in solution- Melting point high → giant structure (ionic, giant covalent or metallic): 801 °C is high.
- Test conduction as a solid: it does not conduct as a solid, so not metallic.
- Conducts when molten or dissolved → ionic: the substance is ionic.