Chapter 14: Thermal Physics Flashcards
What is the Triple Point of a substance?
The Triple Point of a substance is the temperature in which the substance exists as a solid, liquid and a gas in thermal equilibrium.
What is the direction of net flow of thermal energy in two objects?
The direction of net flow of thermal energy is from the hotter object to the colder object.
What is the definition of Thermal Equilibrium?
Thermal Equilibrium is when two objects are the same temperature with not net flow of thermal energy between them.
What is absolute temperature?
Absolute Temperature is a scale of measuring temperature using absolute zero and the triple point of water with equal divisions between the temperatures. The unit is Kelvin, and is equal to Celsius + 273.
What is the kinetic model?
The Kinetic Model is a way of describing how all substances are made of atoms or molecules, and their arrangement based on their state of matter.
Describe the Kinetic Model in Solids.
The Kinetic Model of Solids consists of particles that are regularly arranged in a lattice structure and packed closely together due to strong electrostatic forces. They vibrate within their fixed positions, vibrating vigorously when temperature increases.
What is the Kinetic Model of Liquids?
The Kinetic Model of Liquids consists of particles (or molecules) that are situated close together but are able to freely move around each other, with weak intermolecular forces between particles/molecules. When temperature increases, particles/molecules move around at faster speeds, leading to a higher rate of collisions between particles causing the liquid to expand.
Describe the Kinetic Model of a Gas.
In a Gas, particles have more kinetic energy and are spread far apart with little to no forces of attraction between them. Particles move randomly at high speeds in different directions, and exert pressure on the container when they collide with the walls of the container.
What is Brownian Motion?
Brownian Motion is the random haphazard motion due to elastic collisions between the small particles suspended in a fluid.
What is Density in Thermal Physics?
Density in Thermal Physics refers to the spacing between atoms or molecules within a substance, and is affected by their state of matter, with solid being more dense and gases being less dense (except for water, which forms a crystalline structure that holds molecules away from each other).
What is the definition of Internal Energy?
Internal Energy is defined as the sum of the randomly distributed kinetic and potential energies of atoms or molecules within a substance.
What two types of energy affect total internal energy?
The two types of energy that affect internal energy are Kinetic and Potential energies.
How does the Kinetic, Potential and Internal energy change when temperature is increasing?
When Temperature is increasing, the Kinetic Energy of Particles increase as they move faster and vibrate more rigorously. The (Electrostatic) Potential Energy stays the same as all energy is used to increase kinetic energy. As Internal Energy consists of Kinetic and Potential Energy, Internal Energy increases.
How does Kinetic, Potential and Internal energy change when a substance is changing state?
When a substance is changing state, Kinetic Energy stays the same as all energy is used to break the bonds between particles/molecules. The Electrostatic Potential Energy increases as bonds are breaking. As the Internal Energy is made up of the sum of Kinetic and Potential Energy, internal energy increases.
What is the Electrostatic Potential Energy in Solids, Liquids and Gases?
The Electrostatic Potential Energy in Solids, Liquids and Gases have negative values, with solids having a large negative value, liquids having a negative value, and gases having an Electrostatic Potential of 0 Joules, therefore increasing every time.
