Compare Atomic Structures Practice Test

Comparing these substances: Substance A is oxygen gas ($\mathrm{O_2}$) and Substance B is ozone ($\mathrm{O_3}$). What is the main difference in their particle-level composition?

In the particle models, Substance A is nitrogen gas ($\mathrm{N_2}$) and Substance B is ammonia ($\mathrm{NH_3}$). Which statement best identifies the pattern about element types?