The state of matter in ice cream changes when it melts. The molecules in ice cream lose energy, and become less mobile. The temperature rises as a result. The energy is converted to heat, which makes the ice cream softer and melts more quickly.
Adding energy increases the motion of the molecules
When energy is added to a mixture, the motion of molecules increases. When the energy is removed, the molecules stop moving. The main difference between ice and other liquids is the arrangement of the molecules. Ice molecules are more distant than liquid water. The molecules in solids are closer together than they are in liquid water. When modeling melting and freezing, students can also include condensation and evaporation. It is important to handle the molecules gently.
Water molecules absorb energy from their environment, including heat, as they move through the atmosphere. This energy causes the molecules to vibrate more, which in turn increases their temperature. As the water molecules vibrate more, they break bonds and change from solid to liquid. This process is known as melting. The temperature at which water melts is called the melting point.
Adding energy decreases the motion of the molecules
The kinetic theory of matter states that everything is made up of particles that are constantly in motion. Adding energy to an ice cream slows down this motion and changes the kinetic energy to potential energy. The same goes for hot water bottles or hot baths. Adding energy to them will cool them down, but not generate more energy.
Water molecules move in the same way in liquid and solid states. Adding energy increases their motion while removing energy decreases their motion, causing them to move closer together. Water freezes to ice in a unique way. When it freezes, its molecules move in an open ring pattern. This opens up a space that allows the ice to expand.
Salting ice cream mixtures lowers the phase temperature and lowers their transition temperatures. This happens because the kinetic energy of the molecules determines the temperature of the mixture. Salt reduces the motion of molecules by around 30 degrees Celsius.