Question

Base your answer to the question on the information below and on your knowledge of chemistry. Elements with an atomic number greater than 92 can be artificially produced in nuclear reactions by bombarding a naturally occurring nuclide with a different nuclide. One of these elements is roentgenium, Rg. The equation below represents a nuclear reaction that produces Rg-272. Determine the number of neutrons in an atom of Rg-272. Time on question: 00:01:44

Answer 1

Rg has atomic number 111 on the periodic table. That means it has 111 protons. The 272 in the Rg-272 indicates that it has a mass number of 272. Mass number is the sum of protons and neutrons.

Mass number = # protons + # neutrons

Plugging our values into this equation:

272 = 111 + ?