The diagram shows a model of an atom. The model has four different symbols on it. Each symbol represents a different role for one of the particles within the atom. In this model, which particle determines the reactivity of this atom? Question 18 options:

Particle W

Particle W

Particle Y

Particle Z

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?