Question

the first model of the atom was developed through
scientific experimentation and data analysis with water vapor and gases.
obser vation of the light emitted by elements when they are heated.
thinking about the smallest particles of matter without experimenting.
analyzing the effects of a magnet on the path of a cathode ray.

Explanation:

The first atomic model was the Democritus' concept of atoms, which was developed through philosophical thinking about the smallest particles of matter without experimentation. The other options involve more modern - era experimental methods.

Answer:

thinking about the smallest particles of matter without experimenting.