Question

1. draw the particles before and after melting. 15. in detail what happens to particles befo

Explanation:

Melting is a phase change from solid to liquid. Before melting (in solid state), particles are closely packed in a regular, fixed arrangement (e.g., for a crystalline solid, a lattice structure) with strong intermolecular forces, vibrating in fixed positions. After melting (in liquid state), particles gain enough energy (heat) to overcome some intermolecular forces, move more freely, and have a more random arrangement, though still relatively close compared to gas. To draw:

• Before (Solid): Draw small circles (particles) closely packed in an orderly, repeating pattern (e.g., rows and columns, or a lattice). Use short lines or dots to show limited vibration (e.g., small arcs around each particle).
• After (Liquid): Draw the same number of particles, but spaced slightly further apart, in a more random, irregular arrangement. Show particles with arrows or longer arcs to indicate more movement (sliding past each other).

Answer:

Before Melting (Solid State) Particle Diagram:

Draw a rectangle. Inside, place small, evenly - spaced circles (representing particles) in a neat, ordered pattern (like a grid). Around each circle, draw tiny curved lines to show the limited vibrational motion of particles in their fixed positions.

After Melting (Liquid State) Particle Diagram:

Draw another rectangle (same size or similar to represent the same amount of substance). Inside, place the same number of circles, but arrange them in a more random, scattered pattern (not in a grid). Draw longer, more dynamic curved lines or arrows around the circles to show that particles can move more freely (sliding past one another) as they have gained energy to overcome some intermolecular forces.

(Note: The key is to show the change from ordered, closely - packed particles with limited motion in solid to more random, slightly less closely - packed particles with more freedom of movement in liquid.)