L3 - Zero Law & Temperature

What is the Zeroth Law of Thermodynamics?

If 2 systems are each in thermal equilibrium with a third system, then they are also in thermal equilibrium with each other - which is the fundamental principle that makes temp measurement possible.

If A=B and B=C, then A must equal C

What are the boiling water and melting ice temperatures in the Celsius Scale?

100*C

0*C

What is the formula to transition between Celsius and Fahrenheit?

What is a key rule about atomic energy levels in quantum mechanics?

Atoms can only exist with certain discrete energies - they cannot have just any energy value

In a collection of atoms, how are they distributed across energy states?

Most atoms sit in the lowest (ground) state, with fewer and fewer occupying each successively higher energy state

What is an equilibrium population of atoms?

A state where atoms continuously jump between energy levels but create no net change in the overall population distribution

What is the Boltzmann distribution?

The distribution of atoms over allowed energy states

Boltzmann distribution equation

β = 1/kT

k - Boltzmann's Constant = 1.38x10^-23

What is the population distribution of atoms like at a High T, Low β, and vice versa?

High T, Low β - Many states have significant populations

Low T, High β - Only lower states have significant populations

What does a higher temperature in a Maxwell-Boltzmann Distribution mean?

Broader, flatter curve --> Faster molecules

Lighter molecules move faster on average

What is an ideal gas?

- Theoretical Gas

- Molecules do not attract or repel to each other (can only experience elastic collisions)

- Occupy negligible space

Ideal Gas equation

At higher temperature, molecules will collide more often and faster with boundary walls, leading to higher pressure

T ∝ p, T ∝ V

What is the conversion from Celsius to Kelvin?

T (K) = t(C) + 273.15

What is Heat Capacity?

It is a measure of the ability of a substance to absorb energy transfer as heat