Respuesta :
The correct option is A.
In science, model refers to a representation of idea, object or process which is used to describe a phenomenon that can not be directly observed.
In option A, it can be seen that protons that are inside the nucleus of an atom can not be seen with the naked eyes, that is why scientists used models to represent them.
In science, model refers to a representation of idea, object or process which is used to describe a phenomenon that can not be directly observed.
In option A, it can be seen that protons that are inside the nucleus of an atom can not be seen with the naked eyes, that is why scientists used models to represent them.
The correct option would be
A: Marbles placed inside a hollow sphere are used to describe protons in a nucleus.