To identify the isotope that contains two neutrons in its nucleus, we need to understand the composition of an isotope. An isotope is a variant of a particular chemical element that differs in neutron number. Neutrons are subatomic particles with no electric charge found within the nucleus of an atom.
In this case, an isotope with two neutrons in its nucleus would be Beryllium-7. Here's why:
1. Beryllium has an atomic number of 4, which indicates the number of protons in its nucleus.
2. The mass number of Beryllium-7 is 7, representing the total number of protons and neutrons in its nucleus.
3. By subtracting the atomic number (4) from the mass number (7), we find that Beryllium-7 must have 3 neutrons in its nucleus.
4. Since the question asks for an isotope with two neutrons, Beryllium-7 does not fit the criteria, and we can conclude that Beryllium-7 is not the correct isotope in this case.
Therefore, the isotope that contains two neutrons in its nucleus is Hydrogen-3, also known as Tritium. Hydrogen has an atomic number of 1, and Hydrogen-3 has a mass number of 3, indicating it has two neutrons along with one proton in its nucleus.
