Temperature and phases of matter Flashcards
(13 cards)
What is the definition of heating?
The transfer of energy from a region of higher temperature to one of a lower temperature
What is the definition of thermal equilibrium?
A state in which there is no net flow of thermal energy between the objects involved and all objects must be at the same temperature.
What is the definition for triple point?
At a specific temperature and pressure a substance can exist as the three phases of matter in thermal equilibrium
Define the Celsius scale
A scale for measuring temperature that has units degrees Celsius (oC), and that is defined by the freezing point and boiling point of pure water at atmospheric pressure (1.01 x 103 Pa): 0 oC and 100 oC, respectively.
Define the absolute scale of temperature
A scale for measuring temperature based on absolute zero and the triple point of pure water. Unit is the kelvin. To convert from Kelvin (K) to degrees celsius (°C), the equation is:
K ≈ °C + 273
Define the kinetic model
A model that describes all substances to be comprised of atoms, molecules, or ions that are arranged dependent on the phase of the substance.
Definition of a solid
Highly ordered, closely packed atoms or molecules with very strong electrostatic force of attraction between atoms or molecules. Atoms or molecules can have small vibrations, and therefore have kinetic energy.
Definition of a liquid
No fixed shape, but atoms or molecules still closely packed. Atoms and molecules can flow past each other but there is still electrostatic forces acting between the atoms or molecules. Higher kinetic energy than solids.
Definition of a gas
No fixed shape and atoms and molecules are far apart from each other. Negligible electrostatic forces, so can ignore: therefore atoms and molecules are free to move past each other unless they collide head-on. Gaseous atoms or molecules have high speeds and therefore high kinetic energies.
Definition of Brownian motion
The continuous and random movement of particles suspended in a fluid, visible under a microscope.
Define internal energy
The internal energy is the sum of the randomly distributed kinetic and potential energies associated with the atoms or molecules of a system
In short: internal energy = sum of kinetic energies + sum of potential energies
What is the definition of specific heat capacity?
The specific heat capacity of a substance is defined as the energy required per unit mass to change the temperature by 1K.
What is the definition of specific latent heat?
The specific latent heat of a substance is defined as the energy required to change the phase per unit mass while at constant temperature.
