The states of matter (solid, liquid, gas) are determined by the interplay between two opposing forces: the attractive forces between molecules and the kinetic energy that tends to keep them apart. Understanding this balance is key to identifying the correct answer.
D) The thermal (kinetic) energy of the constituent molecules. This is the opposing factor to intermolecular forces. When kinetic energy is low, attractive forces dominate, forming solids. As kinetic energy increases, it overcomes these forces, leading to liquids and then gases.
The question asks about the defining characteristics of solids. To answer this, we need to recall the fundamental properties of the three common states of matter: solid, liquid, and gas, focusing on shape, volume, and particle arrangement/movement.
Correct Option: A) A definite (fixed) shape and a definite (fixed) volume, due to closely packed particles with very limited freedom of movement. This option accurately describes all the key properties of solids: fixed shape, fixed volume, and the reason behind it (closely packed particles with limited vibrational motion).
The question asks about the characteristic properties of liquids. To answer this, we need to recall the fundamental properties that distinguish liquids from solids and gases, particularly concerning their shape and volume.
B) No definite (fixed) shape, but a definite (fixed) volume, taking the shape of whatever container they occupy. This statement accurately describes the properties of liquids. Liquids flow and conform to the shape of their container, but their volume remains constant under normal conditions.
The question asks about the characteristic properties of gases. To answer this, we need to recall the fundamental differences in the physical properties (shape and volume) of the three common states of matter: solids, liquids, and gases.
A) Neither a definite (fixed) shape nor a definite (fixed) volume, readily expanding to completely fill whatever container they occupy — This statement accurately describes the properties of gases. Gas particles are far apart and move randomly, allowing them to expand and fill any container, thus adopting both its shape and volume.
The question asks to identify the state of matter among the three classical states (solid, liquid, gas) where constituent particles are most closely packed and have the least freedom of movement. This requires understanding the fundamental properties of particles in each state.
In the solid state, particles are held together by strong intermolecular forces, resulting in them being very closely packed. Their movement is restricted to vibrations around fixed positions, thus exhibiting the least freedom of movement. This directly matches the description in the question.
The question asks to identify the specific phase transition where a solid directly converts into a gas, bypassing the liquid phase. We need to recall the definitions of various phase changes.
Correct Option: C) Sublimation is the process where a solid directly changes into a gas without first becoming a liquid. Examples include dry ice (solid carbon dioxide) turning into gaseous carbon dioxide, and naphthalene balls disappearing over time.