Heat transfer in solids occurs mainly by:

**The reasoning** In solids, particles are **tightly packed and vibrating in fixed positions**. When you heat one end of a metal spoon, the particles there vibrate faster. These energetic particles collide with neighboring particles, passing kinetic energy along the solid — this chain reaction is **conduction**. Think of it like a relay race where runners (particles) pass the baton (heat energy) while staying in their lanes. The particles don't move from place to place; only the energy travels through. **Why the wrong options tempt you** - **Convection** needs particles that can *flow* (liquids/gases). Solid particles can't move around, so no convection here. - **Radiation** transfers heat through electromagnetic waves (like the sun warming your skin), but it's not the *main* method in solids — conduction dominates when particles touch. - **Evaporation** is a cooling process involving liquid changing to gas. Not a heat transfer mechanism in solids at all. **Quick takeaway** Solids transfer heat by **conduction** because their particles stay put but pass energy through collisions — like whispering a secret down a crowded row without anyone changing seats.