📚 Key Concepts
Types of Solids- Crystalline (regular arrangement)
- Amorphous (irregular arrangement)
- Polycrystalline
Crystal Systems- Seven basic systems (cubic, tetragonal, etc.)
- Space lattice/Bravais lattices
- Unit cell parameters (a, b, c, α, β, γ)
🎯 Key Formulas
Density Calculationsρ = (Z × M)/(a³ × NA) where:Z = number of atoms per unit cell M = molar mass a = edge length NA = Avogadro's numberPacking Efficiency- Simple cubic: 52.4%
- Body-centered cubic: 68%
- Face-centered cubic: 74%
Radius Ratio Calculations r⁺/r⁻ = radius ratio
⚠️ Common Mistakes to Avoid
Wrong coordination number calculationIncorrect packing efficiency formulasMixing up crystal systemsWrong unit cell countingMisidentifying defect types
📖 Knowledge Prerequisites
3D geometryBasic mathematicsChemical bondingAtomic structureUnit conversions
💡 Tips for Students
Visualize 3D structuresPractice unit cell drawingsLearn formula derivationsUnderstand defect formationRemember radius ratio rules
👉 Practice Recommedations
Calculate density problemsDraw unit cell structuresDetermine coordination numbersSolve packing efficiency questionsIdentify crystal systems
Practice each question with a timer and get instant feedback
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