1. Motion description: Observe the change of the position and velocity of the particle with time. By observing the trajectory and speed change of a particle, we can judge whether it has an accurate trajectory or a specific motion pattern.
2. Physical properties: Observe the physical properties of particles, such as mass and charge. These physical properties can be used to distinguish different particles and judge whether they have specific properties.
3. Interaction: Observe the interaction between particles and other objects or systems. Particles may be subjected to force or collide with other particles. By observing these interactions, we can infer the properties and skills of particles.
4. Mathematical modeling: Mathematical modeling of particle motion, using physical laws and equations to describe the behavior of particles. Through mathematical modeling, we can predict and analyze the motion and interaction of particles, so as to further understand their skills.
Generally speaking, the skill of judging a particle needs to be combined with qualitative and quantitative observation, and analyzed and inferred by using the principles and methods of physics.