Question

Element number 111 is called roentgenil

Which best describes the nucleus of an atom of
this element having a mass of 272 amu?
(1) 272 protons and 111 neutrons
(2) 161 neutrons and 111 protons
(3) 111 neutrons and 272 protons
(4) 111 neutrons and 161 protons

Answer 1

The nucleus of an atom of element 111 with a mass of 272 amu is best described as having 161 neutrons and 111 protons.

Step-by-step explanation:

The element with atomic number 111 is called roentgenium (Rg), not roentgenil. An atom's nucleus is composed of protons and neutrons. The mass number (or atomic mass) of an atom is the sum of the protons and neutrons in its nucleus. Therefore, since the element has a mass of 272 amu, option (2) 161 neutrons and 111 protons would best describe the nucleus of an atom of this element.

Learn more about Nucleus of an Atom