Multiple Choice Question:
Which aspect of Dalton's atomic theory was later found to be incorrect?
A) Atoms are indivisible and indestructible. B) All atoms of a given element are identical in mass and
properties. C) Atoms of different elements combine in simple whole-number ratios to form compounds.
D) Atoms of one element can change into atoms of another element through chemical reactions.
Explanation:
The correct answer is D) Atoms of one element can change into atoms of another element through
chemical reactions.
Dalton's atomic theory, proposed by John Dalton in the early 19th century, was a significant step in
understanding the nature of matter. It had several key postulates, including:
A) Atoms are indivisible and indestructible: This statement is generally considered accurate for most
chemical reactions, as atoms are not broken apart into smaller subatomic particles in chemical reactions.
B) All atoms of a given element are identical in mass and properties: This is largely true, although
isotopes can have slightly different masses due to variations in the number of neutrons.
C) Atoms of different elements combine in simple whole-number ratios to form compounds: This is a
fundamental principle in chemistry, and it remains valid.
D) Atoms of one element can change into atoms of another element through chemical reactions: This
postulate is incorrect. It was later discovered that atoms can change from one element to another
through nuclear reactions, such as nuclear decay or fusion. These processes can alter the number of
protons in the nucleus, changing the element itself.
So, option D is the correct answer because it reflects the aspect of Dalton's atomic theory that was later
found to be inaccurate due to our understanding of nuclear reactions.
