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

To find the number of neutrons in Roentgenium-272 (Rg-272), subtract its atomic number (111) from its mass number (272), resulting in 161 neutrons.

The student is asking to determine the number of neutrons in an atom of Roentgenium-272 (Rg-272). To calculate the number of neutrons in an atom of Rg-272, we use the mass number of the isotope and the atomic number of the element.

Roentgenium (Rg) has an atomic number of 111, which is the number of protons in the nucleus of the atom. The mass number of Rg-272 is the sum of protons and neutrons together. Since we know the atomic number of Rg is 111, the calculation to find the number of neutrons is:

Number of neutrons = Mass number - Atomic number
Number of neutrons = 272 - 111
Number of neutrons = 161

Therefore, an atom of Rg-272 has 161 neutrons.

Answer 2

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 + ?