A radioactive element ²⁴²₉₂X emits two α-particles, one electron and two positrons. The product nucleus is represented by ²³⁴ₚY. The value of P is ____.
Physics · Circular Motion
JEE Mains 29 January 2023 Shift 1 Morning Shift

Question

A radioactive element ²⁴²₉₂X emits two α-particles, one electron and two positrons. The product nucleus is represented by ²³⁴ₚY. The value of P is ____.

G1 Physics · Accepted Answer

Two α-emissions reduce atomic number by 4. One β⁻ emission increases it by 1, while two β⁺ emissions reduce it by 2. Thus P = 92 − 4 + 1 − 2 = 87.