The sealed bottle serves as an open system for the water molecules, thus heat energy can be exchanged with its surroundings. When the bottle is placed in a warm environment, there would be a gradual increase in the thermal energy of the molecules of water due to a change in the temperature of its surroundings.
Thus, the molecules of water closer to the boundary of the bottle absorbs heat, becomes lighter and changes position. This gradual process continues until all molecules attains an average temperature which equals that of the surroundings of the bottle.
Therefore, both the thermal energy and temperature of the water increases.
A metal such as copper is a <u>conductor</u> because it provides a pathway for electric charges to move easily. A material such as rubber is an <u>insulator</u> because it <u>resists</u> the flow of electric charges. A material that partially conducts electric current is a <u>semiconductor</u>. These materials include <u>group 3 and group 5</u> elements.
