What is the isotope notation for a nucleus with 5 protons and 2 neutrons?

Answer 1

The isotope notation for a nucleus is represented as \[ \text{A}^{\text{Z}}X \], where:

• \( A \) is the mass number (the total number of protons and neutrons),
• \( Z \) is the atomic number (the number of protons),
• \( X \) is the chemical symbol for the element.

For a nucleus with 5 protons and 2 neutrons:

1. The number of protons (\( Z \)) is 5, which corresponds to the element boron (B).
2. The number of neutrons is 2.
3. The mass number (\( A \)) is the sum of protons and neutrons: \( A = 5 + 2 = 7 \).

Thus, the isotope notation for this nucleus is \[ \text{B}^{7}_{5} \] or more commonly written as \[ \text{^7B} \].