Uranium-238 undergoes alpha decay. What are the mass number and atomic number of the daughter nucleus?

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Question

Uranium-238 undergoes alpha decay. What are the mass number and atomic number of the daughter nucleus?

Accepted Answer

Mass number 234, atomic number 90 — Alpha decay removes 2 protons and 2 neutrons. Uranium has atomic number 92 and mass number 238, so the daughter has mass number 238 − 4 = 234 and atomic number 92 − 2 = 90, which is thorium-234.

Answer

Mass number 234, atomic number 92

Answer

Mass number 236, atomic number 92

Answer

Mass number 234, atomic number 90

Answer

Mass number 236, atomic number 90

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