Temperature and Phases of matter Flashcards
Define Heating.
The transfer of energy from a region of higher temperature to one at a lower temperature.
Define thermal equilibrium.
A state in which there is no net flow of thermal energy between two systems is considered to be in “thermal equilibrium”.
Define the Triple point.
A specific temperature and pressure where the three phases of matter can exist in thermal equilibrium.
Define the Celsius Scale.
A scale for measuring temperature and has units degrees Celsius and that is defined by the freezing point and boiling point of pure water at atmospheric pressure.
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 the equation is K = degrees C +273.
State the Kinetic model.
A model that describes all substances to be made up of of atoms, molecules, or ions that are arranged dependent on the phase of the substance.
Define 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 a small vibration and therefore have kinetic energy.
Define a liquid.
No fixed shape, but atoms or molecules still closely packed. Atoms and molecules can flow pst each other but there is still electrostatic forces acting between the atoms or molecules. Higher kinetic energy than solids.
Define 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 that have high speeds and therefore have high kinetic energies.
State what is Brownian Motion.
The continuous and random movement of particle suspended in a fluid, visible under a microscope.
Define Temperature.
The average kinetic energy of particles in a system.
Define Internal energy.
The sum of the random Distribution of kinetic and potential energies associated with the molecules/particles of a system.
Define absolute zero.
0K (kelvin) or -273.15°C (degrees Celsius). Here, there is minimum internal energy and zero kinetic energy.
