Final answer:
The element with 5 neutrons, 3 protons, and 3 electrons is an isotope of Lithium, but not the well-known Lithium-6 isotope. Instead, it would have a mass number of 8.
Step-by-step explanation:
The element with 5 neutrons, 3 protons, and 3 electrons is an isotope of Lithium, specifically Lithium-6. The number of protons in an atom defines the element, and with 3 protons, it is Lithium (Li). The mass number of an atom is the sum of its protons and neutrons, thus Lithium-6 has a mass number of 6 (3 protons + 3 neutrons). The isotope of Lithium with 3 protons and 5 neutrons does not have a specific name but it would have a mass number of 8 (3 protons + 5 neutrons).
Lithium has several isotopes, and in school curriculum, Lithium-6 and Lithium-7 are commonly discussed. In the case of Lithium-6, its isotope symbol can be written as '6Li or Li-6. Understanding isotopes and their representation is fundamental in chemistry education.