Final answer:
Dalton's statement that all atoms of an element are identical in mass and properties is partially true. Atoms of the same element share similar properties but can have different masses due to varying numbers of neutrons, leading to different isotopes.
Step-by-step explanation:
The statement from
Dalton's atomic theory
that 'all atoms of an element are identical and have the same mass and properties' is partially correct, but not entirely. While this assertion was accurate based on the scientific knowledge at the time of Dalton, we know today that it's a bit more complex. Atoms of the same element do share similar properties, however, they can have varying masses due to different numbers of neutrons -- these variations are known as
isotopes
. For instance, carbon-12, carbon-13, and carbon-14 are all isotopes of carbon with varying numbers of neutrons, so they have different masses.
Learn more about Dalton's Atomic Theory