Explore materials that explain the nature of the internal energy of bodies and how it changes when the temperature rises or falls, as well as in chemical reactions. Answer the questions.
All particles of matter affect each other - there are attractive and repulsive forces between the particles of matter. It helps to understand such forces if we imagine that there are springs attached between the particles of matter. When we push the balls closer together, the spring creates a thrust force that pushes the balls away from each other. When we stretch the balls away from each other, the spring creates a tensile force that pulls the balls closer together. The interaction between the particles of matter imparts potential energy to the particles of matter in much the same way that all bodies possess potential energy due to the gravitational pull of the Earth.
We know from mechanics that the greater the speed of a body, the greater the kinetic energy of its movement. We know from the past that the higher the particle movement speed, the higher the body temperature. So we can say that the higher the temperature of the body, the greater the kinetic energy of the particles of matter.
The sum of the kinetic and potential energy of the particles of matter is called the internal energy of the body. If the state of matter does not change, the internal energy of the body increases as the temperature rises, i.e. the kinetic energy of the particles of matter changes. If the state of matter changes, then both the potential and kinetic energy of the particles of matter change:
- In solids, the kinetic energy of the particles of matter is much smaller than the potential energy of the attractive forces acting between the particles.
- In liquids, the kinetic energy of the particles of matter is approximately the same as the potential energy of the attractive forces acting between the particles.
- In gases, the kinetic energy of the particles is much greater than the potential energy of the attractive forces between the particles.
Simulatsiooni avamiseks kliki pildile. Simulatsiooni käivitamiseks vajuta kolmnurgaga nupule. Nuppudega „Cool" ja „Heat" saad vastavalt temperatuuri tõsta või langetada. Vajutades „Show partial charges" muudad nähtavaks vee molekulide osalaengud. Vajutades „Slow motion" lülitub simulatsioon aegluupi.
Simulatsiooni avamiseks kliki pildile. Simulatsiooni käivitamiseks vajuta kolmnurgaga nupule. Vajutades „Slow motion" lülitub simulatsioon aegluupi. Simulatsiooni alumises servas on graafik, millel on kasutatud lühendeid KE - kineetiline energia (punane graafik), PE - potentsiaalne energia (roheline graafik), TE - kogu siseenergia (sinine graafik).