Internal Energy And Changes Of State Flashcards
Change in thermal energy (j)
🔺E=mc🔺O (theta)
Change in thermal energy (j) = mass (kg) x specific heat capacity (J/kg•C) x temperature change (•C)
What do the particles in a system do
The particles in a system vibrate or move around-they have energy in the kinetic energy stores
What do the particles in a system also have?
They also have energy in their potential energy stores due to their positions
The energy stored in the system is stored by?
It’s particles (atoms and molecules)
What is the internal energy of a system?
The internal energy of a system is the total energy that particles have in their kinetic and potential energy stores
Heating the system
Transfers energy to its particles (they gain energy in the kinetic stores) and move faster increasing internal energy
What does heating the system lead to?
A change in temperature or changing state. If the temperature changes, the size of the change depends on the mass of a substance, what it’s made of (specific heat capacity).
A change in state occurs…
If the substance is heated enough-the particles will have enough energy in their kinetic energy stores to break the bonds holding them together.
What happens when you heat a liquid?
It’s boils or evaporates and becomes a gas.
What happens when you heat a solid?
It melts and becomes a liquid
The stage can also change due too…
Cooling. The particles lose energy and form bonds
how do you get from a solid to a gas?
Sublimating.
What is a change of state?
Are physical change rather than a chemical change this means you don’t end up with a new substance-it’s the same substance as you started with, just in a different form.
If you reverse a change of state…
The substance will return to its original form and get back its original properties.
When reversing a change of state, The number of particles…
Doesn’t change-they are just arranged differently. This means mass is conserved. none of it is lost when a substance changes state
