alleryWhich scientist showed using X-ray experiments that the atomic number equals the positive charge on the nucleus?
ADobereiner
BDmitri Mendeleev
CJohn Newlands
DHenry Moseley
Answer & Solution
Correct answer: D. Henry Moseley
1. In 1913 Henry Moseley experimented with an X-ray tube.
2. He showed the atomic number (Z) equals the nuclear positive charge, i.e. the proton count.
3. This revealed atomic number to be more fundamental than atomic mass.
4. Rule out B: Mendeleev's table predated knowledge of the atom's interior.
_Source: Balbharati (Maharashtra Board) Class 10 Science & Technology, Ch 2 "Periodic Classification of Elements", p.29_
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