Types of chemical bond and crystal lattices
Answers are for parents and teachers.
1
How many σ bonds are there in ethene (C₂H₄)?
5
2
Find the electronegativity difference in MgO (Mg 1.3; O 3.4). What is the bond type?
2.1 — ionic bond.
3
Why are ionic crystals brittle yet conduct electricity when molten?
If a layer of ions shifts, like charges come side by side and the crystal breaks; in the melt the ions are mobile.
4
How many σ and π bonds are there in a CO₂ molecule (O=C=O)?
2 σ and 2 π.
5
Explain the difference between a nonpolar and a polar covalent bond with one example each.
Nonpolar: Cl₂ (the pair does not shift); polar: HCl (the pair shifts toward Cl).