what has a definite shape and volume

a- solid

b- liquid

c- gas

d- molecule

My answer is A

Yes.

Your answer is correct. A solid has a definite shape and volume.

To determine the answer to this question, it is important to understand the basic characteristics of each option.

A solid is a state of matter in which the particles are closely packed together and have a fixed shape and volume. Examples of solids include rocks, metals, and wood.

A liquid, on the other hand, has a definite volume but takes the shape of its container. The particles in a liquid are not as closely packed as those in a solid and can move more freely. Water, oil, and milk are examples of liquids.

A gas has neither a definite shape nor volume and can fill the entire space available to it. Gas particles are not very closely packed and are highly energetic. Examples of gases include oxygen, nitrogen, and carbon dioxide.

"Molecule" refers to the smallest unit of a substance that retains its chemical properties. However, it does not have a definite shape or volume on its own.

Therefore, among the given options, only a solid has both a definite shape and volume.