The ionic bond. Crystal lattices
Answers are for parents and teachers.
1
Write the formula of the compound from Al³⁺ and O²⁻ ions and check the charges.
Al₂O₃: 2·(+3) + 3·(–2) = 0
2
How many electrons must Li give, and which noble gas configuration does it get?
1; helium (2).
3
Give the lattice type for NaCl, CO₂, diamond and copper.
NaCl — ionic; CO₂ — molecular; diamond — atomic; copper — metallic.
4
Why is an ionic crystal brittle?
When a layer shifts, ions of the same charge come side by side and repel, so the crystal cracks.
5
Why does solid NaCl not conduct current while its solution does?
In the solid the ions are fixed at the sites; in solution they move freely.