Intermolecular Forces V/S Thermal Interactions
Chapter Name : States Of Matter |
Sub Topic Code : 102_11_05_04_01 |
Topic Name : Intermolecular Forces V/S Thermal Interactions |
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Sub Topic Name : Intermolecular Forces V/S Thermal Interactions |
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Introduction
• Intermolecular forces tend to keep the molecules together but thermal energy of the molecules tends to keep them apart. • When molecular interactions are very weak, molecules do not cling together to make liquid or solid unless thermal energy is reduced by lowering the temperature. The 3 states of matter are the result of balance between intermolecular forces and thermal energy of the molecules.
Pre-Requisites:
molecule, kinetic energy, particle, thermal energy
Activity:
Condensation over a glass of cold water kept on a table.
Real Life Question:
How do substances become solid, liquid or gaseous?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Thermal energy | The energy of a body arising from motion of its atoms or molecules. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Put a cold glass of water on the table | After a while you would see tiny droplets appearing on the surface of the water. This is called condensation of the water vapor present in the air. |
Real life uses :
Gas is easily compressed at high pressure and it still remains a gas.
Places to visit :
kitchen
Practical examples around us
| Examples | Explainations |
|---|---|
| Condensation over a glass of cold water | Water vapor in the air condenses over the surface of a glass of cold water. |
What you learn in Theory:
Therefore, the 3 states of matter are the result of balance between intermolecular forces and thermal energy of the molecules.
What you learn in Practice:
Condensation of water vapor occurs only when the temperature is reduced.