Question

Why does a solid have a definite shape?

The particles of a solid vibrate in fixed positions.
The particles of a solid have no forces of attraction between them.
The particles of a solid cannot change shape.
The particles of a solid cannot move at all.

Answer 1

a solid has a definite shape because it's particles are vibrating at a mean fixed position,
A is your answer

Answer 2

The particles of a solid vibrate in fixed positions.

Step-by-step explanation:

Solids are a phase of matter. Other phases of matter include liquids, gases and plasma. The key defining feature of each of the phases are the inter-molecular forces of attraction. Solids have the strongest inter-molecular forces among the three.

Solids have thermal energy which results in their atoms to vibrate in their fixed mean positions.