Which of the following describes a scalar?

A scalar is best described as a quantity that only has magnitude. Scalars are values that can be described by a number with a unit, such as temperature (e.g., 20 degrees Celsius), mass (e.g., 5 kilograms), or distance (e.g., 10 meters). These quantities do not have a directional component; they simply provide a measure of how much or how many.

In contrast, other options introduce concepts related to direction or specific types of quantities. A quantity with both magnitude and direction is defined as a vector. A vector with zero length is a special case of a vector and is not a scalar; it still implies directionality to some extent. A point in space can be represented in terms of coordinates but does not inherently describe a physical quantity with magnitude.

Recognizing that scalars focus solely on how much – without the necessity of direction – distinguishes them from other types of quantities in physics and mathematics.