\(^{226}_{88}Ra\) \(\to\) \(^{222}_{86}Rn\) + X + Energy. The equation above represents a nuclear decay of radium isotope. What is X?
A
Alpha particle
B
Beta particle
C
Gamma ray
D
Neutron
E
X – ray
Verified Correct Answer: A.
Physical Principles & Numerical Solution
Mass Number: The mass number on the left side is 226 (from Ra) and 222 (from Rn) on the right side. Let A be the mass number of X:
226 = 222 + A ⇒ A = 226 - 222 = 4
Atomic Number: The atomic number on the left side is 88 (for Ra) and 86 (for Rn) on the right side. Let Z be the atomic number of X:
88 = 86 + Z ⇒ 88 - 86 = 2
Therefore, X is an alpha particle.
Source: Myschool Past Questions Archive (Record #42915)