A drop of dye sinks into a beaker of still water. In the morning the dye is one dark bead. By evening it tints the whole beaker evenly.
Same dye, same water, two very different arrangements. Physics has a measure for the difference.
In the morning, the dye's matter is concentrated in one spot. In the evening, the same dye is spread through all of the water.
Energy can be arranged the same two ways. Thermal energy can sit concentrated in one hot object, or lie spread across everything in a room.
A dispersed arrangement has greater entropy than a concentrated one.
So the beaker in the evening has greater entropy than the same beaker had in the morning. Only the arrangement changed.
Entropy is not an amount of energy. It measures how spread out the energy and matter are, not how much there is.
No number is needed in this topic. Comparing two arrangements, the more dispersed one has the greater entropy.
The air in a sealed gym fills the gym evenly. Picture the same air crowded into one corner instead. Which arrangement has greater entropy?
The air filling the gym evenly is the more dispersed arrangement.
A dispersed arrangement has greater entropy than a concentrated one.
The evenly filled gym has greater entropy than the crowded corner.
A cast-iron pot holds 500 J of extra thermal energy. Later, the same 500 J lies shared across the pot, the stove top, and the kitchen air. When is the entropy of the pot plus the kitchen greater?
The amount of energy is the same at both moments: 500 J.
Shared across the pot, the stove top, and the air, the energy is more spread out.
A dispersed arrangement has greater entropy than a concentrated one.
Later, when the 500 J is shared, the entropy is greater.
A mug of milk holds a spoonful of cocoa powder. Earlier, the cocoa sat in one dark patch; later, it is mixed evenly through the milk. When is the mug's entropy greater?
Harriet says: 'The same amount of thermal energy has greater entropy spread through a whole pool than gathered in one warm patch.' Is she correct?
The same 400 J of thermal energy can be arranged four ways in a workshop with a soldering iron. Which arrangement has the greatest entropy?
Which of the following statements about entropy is correct?
A dishwasher is opened, its steam spreads through the kitchen, and its thermal energy spreads into the air. Afterward, the steam and the energy are more spread out than before. How does the entropy of the dishwasher plus the kitchen compare with before?
There is a measure of how spread out a system's energy and matter have become. What is this measure called?