A pure substance is one that contains only one type of atom or chemical molecule (the opposite of a mixture).Pure substances such as water (H2O) can be found in 3 forms solidliquidgaseous Water has the advantage of being naturally present on Earth in these 3 forms, because its properties allow it to be at ambient temperature. This is not the case for other substances, which require extreme conditions to change state, such as : copper: solidoxygen : gaseousethanol: liquid For example, for oxy...

The second principle of thermodynamics allows us to know if a system will evolve spontaneously. It introduces a new concept: entropy. It is a rather abstract notion, often seen as a measure of disorder. First of all, it is important to define the state of equilibrium: a system is said to be in equilibrium when it is stable and invariant, for an indefinite period of time as long as an external event does not intervene. A transformation is said to be reversible if at any time there is equilibriu...

Thermodynamics is based on three principles: temperature (or the zero principle)the first principlethe second principle If we say that temperature is the zero principle, it is because this notion has often been used without being really defined. The first principle, which we are going to see today, is neither more nor less than the conservation of energy. It may seem trivial, but it allows us to see properties that are not so obvious. To apply the first principle of thermodynamics, we start ...

Pressure and temperature are the basis of thermodynamics. Pressure allows us to calculate the forces exerted on the object and thus to account for the work and energy exchanged. While the temperature gives an account of the energy stored. Over time, several tools have been developed to measure pressure and temperature in a relative way. From the manometer or barometer for pressure to the thermometer for temperature. For the temperature, the absolute zero was fixed as the passage from the solid s...

In the middle of the 20th century, home heating was mainly based on the combustion of low-cost fossil fuels.How did heat pump heating develop at that time?The history of heat pumps began in the 20th century with the development of fluid compression refrigeration machines.In France, it was only in 1950 that households installed refrigerators on a massive scale. Incredible when you think about it, it is extremely recent, we wonder how people did to live before. It is the symbol of the comfort of f...

An energy issueFacing increasing shortages and rising fossil fuel prices, better energy management is becoming essential. We are facing a climate crisis linked to human activity. The level of CO2 in the atmosphere is constantly increasing, the oceans are storing a lot of heat and releasing it only very gradually.The rise in temperature is causing :the rise of the sea levelthe melting of glaciers and ice floesthe increase of extreme events such as wildfireClimate change has already begun, and it ...

The main reasons I chose this topic are:I had to find a topic! (and here, I was at the limit in terms of timing, I write this text on August 1st knowing that I should have had it in April)This is one of the chapters where I was the least bad in physics (and physics is probably one of the subjects where I failed the least this year)It's a more easily accessible subject (compared to my first choice in computer science on zero-knowledge proofs where I would have had to type 20000 lines of code and ...