Question

question 1 of 28
the particles of a substance stay close together but slide past one another as
they move. when thermal energy is added to the substance, the particles
start to move independently of one another. what change in state has
occurred?
a. liquid to gas
b. solid to liquid
c. solid to gas
d. liquid to solid

Explanation:

In a liquid, particles are close together and can slide past one another. In a gas, particles move independently. Adding thermal energy (heat) to a liquid provides the particles with more kinetic energy. This increased energy allows the particles to overcome the intermolecular forces that keep them relatively close - packed and sliding (in the liquid state) and move independently (in the gas state).

• Option B: Solid to liquid - In a solid, particles are in a fixed, orderly arrangement. When going from solid to liquid, particles start to move more freely but still have some intermolecular forces. This is not the case described (particles moving independently).
• Option C: Solid to gas (sublimation) - Skipping the liquid state. But the initial state described (particles close together and sliding) is a liquid, not a solid.
• Option D: Liquid to solid - Particles would move less freely (arrange in a more fixed pattern), not start moving independently.

Answer:

A. Liquid to gas