Chapter U3.9, Problem 1E

Interpretation Introduction

Interpretation: Comprehend the three pieces of evidence that air exerts pressure.

Concept Introduction: Matter can exist in three possible states of matter; solid, liquid and gases.

Solids are the substances with least intermolecular distance and strongest intermolecular forces whereas gases have largest intermolecular distance and weakest intermolecular forces. Liquids have intermediate value of intermolecular distance and intermolecular forces.

These states of matter can interconvert into each other and is called as interconversion of states of matter.

Answer to Problem 1E

• During storms, the uplifting of house roofs proves that air exerts pressure.
• Due to air pressure, the car tiers can bear the weight of car.
• The inflation of balloon is also proved the presence of air pressure.

Explanation of Solution

Gases particles have largest intermolecular distance between gaseous particles. Due to high kinetic energy, gaseous particles move freely and can escape from an open container. The presence of gases is difficult to predict yet not impossible. Due to random movement of gas particles, they exert pressure on the wall of container. Air is also a mixture of gases. Three evidence in support of air pressure are:

• During storms, the uplifting of house roofs proves that air exerts pressure.
• Due to air pressure, the car tiers can bear the weight of car.
• The inflation of balloon also proves the presence of air pressure.