Our understanding of the atom has changed over time. which idea that was once accepted is now considered scientifically inaccurate?
a. the nucleus is the center of the atom.
b. an atom is solid material.
c. electrons have a negative charge.
d. electrons are arranged in layers.

I think the correct answer among the choices presented above is option B. The idea that was once accepted is now considered scientifically inaccurate is that an atom is a solid material. This is because now an atom is seen as a particle that has electrons orbiting around a nucleus. It has more like a cloud-like structure.

It maybe because uranus is made of gas but uranus has a solid core in the middle