SCIENCE
PHYSICAL SCIENCES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Its molecules move farther apart
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Its molecules move closer together
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The speed of its molecules decreases
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The temperature decreases although heat is added
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Detailed explanation-1: -When a solid melts, liquid state is obtained. The intermolecular distance in liquid is more than the intermolecular distance in solid. In other words, during melting, the molecules move farther apart. Due to this, the strength of intermolecular forces of attraction decreases.
Detailed explanation-2: -Melting is a process that causes a substance to change from a solid to a liquid. Melting occurs when the molecules of a solid speed up enough that the motion overcomes the attractions so that the molecules can move past each other as a liquid.
Detailed explanation-3: -As the kinetic energy increases, the temperature of the solid increases. As a result, the force of attraction between the molecules decreases and the molecules become more and more separated. This increases the potential energy of the molecule and the particles leave their fixed positions and start moving more freely.
Detailed explanation-4: -During melting, energy goes exclusively to changing the phase of a substance; it does not go into changing the temperature of a substance. Hence melting is an isothermal process because a substance stays at the same temperature.