Which of the following is not a vector quantity?

Mass is a scalar quantity, which means it has magnitude but no direction. The value given (2 kg of mass) solely describes the amount of matter present in an object without addressing any directionality. In contrast, other options provided in the question—velocity, force, and displacement—are vector quantities. They have both magnitude and direction: velocity indicates how fast something is moving and in what direction, force applies a certain amount of push or pull in a specific direction, and displacement represents the change in position, also involving a directional component. This distinction clearly highlights why mass is not considered a vector quantity.