Matter in our surroundings · हमारे आस-पास के पदार्थ
A free Chemistry lesson for Class 9 children.
Matter is made of tiny particles that are always moving.
In a solid the particles are packed closely and only vibrate in place.
In a liquid the particles can slide past each other, so liquids flow.
In a gas the particles are far apart and move freely in all directions.
Ice melts at 273 kelvin and water boils at 373 kelvin.
Latent heat is the heat used to change state without a rise in temperature.
Sublimation is the change of a solid directly into a gas.
Evaporation takes place at the surface of a liquid and causes cooling.