Let F_pp, F_pn and F_nn denote the magnitudes of net force by a proton on a proton, by a proton on a — Nuclear Chemistry and Radioactivity Chemistry Question
Question
Let F_pp, F_pn and F_nn denote the magnitudes of net force by a proton on a proton, by a proton on a neutron and by a neutron on a neutron respectively. Neglect gravitational force. When the separation is 1 fm,
💡 Solution & Explanation
Step 1 - Strong Nuclear Force and Charge Independence The strong nuclear force ($F_n$) at a separation of $1\text{ fm}$ is charge-independent: $$F_{n(pp)} = F_{n(pn)} = F_{n(nn)} = F_n$$ Step 2 - Electrostatic Force Protons carry charge $+e$, so two protons experience repulsive electrostatic force $F_e$ opposing the nuclear attraction. Neutrons are neutral, so $F_{e(pn)} = F_{e(nn)} = 0$. Step 3 - Net Forces - $F_{pp} = F_n - F_e$ (repulsion reduces net force) - $F_{pn} = F_n$ - $F_{nn} = F_n$ Since $F_e > 0$: $F_{pp} < F_{pn} = F_{nn}$ \boxed{D}