JAMB - Physics (1989 - No. 33)
Eight alpha decays and six beta decays are necessary before an atom of 2 \(^{238}_{92}U\) achieves stability. The final product in the chain has an atomic number of
70
78
82
90
Paskaidrojums
U \(\to\) 8(\(^{4}_{2}He\)) + 6(\(^{0}_{-1}e\)) + \(^{b}_{a}X\)
92 = (8 X 2) + (6 X -1) + a
a = 82
92 = (8 X 2) + (6 X -1) + a
a = 82