Question

1. long ago, scientists theorized that each atom was solid like a tiny marble. the atomic theory is still used today, but is modified because--

experiments provided evidence that atoms consist of a dense center surrounded by mostly empty space

people have larger brains than they did in the past so they can think more

photographs of atoms show that atoms look like our solar system

scientists thought that solid atoms would be too heavy to make up gases

clear all

Explanation:

To solve this, we analyze each option:

• Option 1: Scientific theories are modified based on experimental evidence. Atomic experiments (like Rutherford's) showed atoms have a dense nucleus (center) with electrons in mostly empty space, contradicting the "solid marble" idea. This is valid.
• Option 2: Human brain size hasn't significantly increased over time in a way that drives scientific theory modification. This is illogical.
• Option 3: We can't take photographs of atoms at that scale to see their structure like the solar system. The atomic model (like Bohr's) is a theory, not based on direct photos.
• Option 4: The modification of atomic theory isn't due to a concern about gas composition and atom weight, but experimental evidence about atomic structure.

Answer:

A. experiments provided evidence that atoms consist of a dense center surrounded by mostly empty space