Question

John dalton thought that what unit, which means "indivisible", could not be divided into smaller, simpler particles?

Answer 1

atom

Scientists have long wanted to find the most basic building blocks of the universe. They asked, what are the fundamental particles of matter that cannot be subdivided into smaller, simpler particles, and what holds these particles together? The quest for fundamental particles began thousands of years ago. Scientists thought they had finally found them when John Dalton discovered the atom in 1803  see the timeline in Table below  . The word atom means indivisible, and Dalton thought that the atom could not be divided into smaller, simpler particles.