What is the atomic number (Z) of the isotope 7_3Li?

• A. 10
• B. 7
• C. 3
• D. 4

Answer: (C)

Verified step by step guidance

1. Identify the notation of the isotope given: \(^{7}_{3}\text{Li}\). Here, the subscript (3) represents the atomic number (Z), and the superscript (7) represents the mass number (A).
2. Recall that the atomic number (Z) is the number of protons in the nucleus of an atom, which defines the element.
3. The mass number (A) is the total number of protons and neutrons in the nucleus.
4. Since the atomic number is the subscript in the isotope notation, the atomic number (Z) of \(^{7}_{3}\text{Li}\) is 3.
5. Therefore, the atomic number corresponds to the number of protons, which is 3 for lithium in this isotope.