Types of Machines - JSS2 Basic science Past Questions and Answers - page 2

The kinetic theory states that when matter is heated, the particles within it gain kinetic energy, causing them to move faster and further apart, leading to expansion.

Boiling occurs when the vapor pressure of the liquid equals the atmospheric pressure. The kinetic theory explains this as high-energy particles at the liquid's surface breaking free to form bubbles, creating vapor pressure that matches the atmospheric pressure, leading to boiling.

Evaporation occurs at any temperature, with high-energy particles escaping from the liquid's surface. Boiling, on the other hand, happens when the entire liquid reaches its boiling point, and bubbles form throughout due to the vapor pressure equalling atmospheric pressure.

In evaporation, particles with sufficient energy break free from the liquid's surface to form vapor. The kinetic theory explains that it is the high-energy particles that escape, reducing the average kinetic energy and thus cooling the remaining liquid.