1g-Covalent bonding Flashcards
Question: What is covalent bonding?
Answer: Covalent bonding is the sharing of electrons between two non-metal atoms to achieve a full outer shell.
How are covalent bonds formed?
Answer: Covalent bonds form when atoms share pairs of electrons. Each shared pair represents one covalent bond.
Question: What is a molecule?
Answer: A molecule is a group of atoms held together by covalent bonds.
Question: How is a covalent bond represented in a dot-and-cross diagram?
Answer: A dot-and-cross diagram shows shared electrons as dots and crosses between atoms. Example: H₂O shows oxygen sharing electrons with two hydrogen atoms.
Question: What are the properties of covalent compounds?
Answer:
Low melting and boiling points due to weak intermolecular forces.
Do not conduct electricity because they have no free electrons or ions.
Usually soft and brittle.
Question: What is the difference between simple molecular and giant covalent structures?
Answer:
Simple molecular: Small molecules with weak intermolecular forces (e.g., H₂O, CO₂).
Giant covalent: Large networks of atoms with strong covalent bonds (e.g., diamond, graphite, silicon dioxide).
Question: Why do giant covalent structures have high melting points?
Answer: They have strong covalent bonds throughout the structure that require a lot of energy to break.
Question: Why can graphite conduct electricity but diamond cannot?
Answer: Graphite has free electrons that can move between layers, allowing it to conduct electricity. Diamond has no free electrons.
Practical: Investigating the Properties of Covalent Compounds
Method:
Measure melting points of covalent compounds.
Test electrical conductivity in both solid and liquid states.
Practical: Investigating the Properties of Covalent Compounds
Results
:
Positive Result: Low melting points and no electrical conductivity.
Negative Result: High melting points and conductivity indicate ionic or metallic substances.
