Question

Which of the following parts of John Dalton’s atomic theory, if correct, would have made it impossible for Marie Curie’s discovery that new elements can be produced when elements are bombarded with neutrons?

All matter is made of atoms.

The atom is the smallest particle of matter.

Atoms of the same element are different from atoms of other elements.

Chemical change involves the rearrangement of atoms.

Answer 1

"The atom is the smallest particle of matter."

If atoms were truly indivisible and the smallest possible particles, you could not change one element into another by breaking or altering atoms. Marie Curie's neutron bombardment causes changes in atomic nuclei (nuclear reactions) that produce new elements — processes impossible if atoms were absolutely indivisible. The other statements do not rule out nuclear transmutation (the chemical-rearrangement point refers only to chemical, not nuclear, changes).