The speed at which a particle moves is measured by its?

Velocity

Explanation:

In the context of speed, this refers to the change of position in a fixed amount of time, and velocity provides more depth to that; it also gives direction, which makes sense when you eventually learn that the velocity is the derivative of the position.

In physics, velocity is prevalently used.

the electron configuration that you gave me has 16 electrons ergo it has 16 protons ergo it is the element sulfur.