233U92 → AAc89 + 2α particles + β particle. What is the value of A?

233U92 → AAc89 + 2α particles + β particle. What is the value of A? Correct Answer 225

CONCEPT:

• In nucleus of an atom there are protons and neutrons.
  • Number of protons = Atomic number of an element.
  • Nuclei = neutron + proton

• The number of protons and number of electrons are equal in a neutral atom.

Radioactive nuclear decay: Radioactive nuclear decay is the process by which an unstable isotope of a particular element spontaneously transforms into a new element by the emission of ionizing radiation. Example: Decay of C-14 to C-12.

• α-decay: An alpha particle consists of two protons and two neutrons, which is a helium nucleus. Losing the protons and neutrons makes the nucleus more stable.
• β-decay: Beta decay is a type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus.
• γ-decay: it neither changes the atomic number nor atomic mass.

EXPLANATION:

From the above explanation, we can see that in alpha decay one helium atom is ejected from an atom 

i.e., AXZ → A-4XZ-2 + 4He2

Hence in our case, the value of A can be predicted by equating the number of nucleons before and after alpha-decay 

i.e., 233 = A + 2x4 ⇒ A = 225

Thus the reaction can be expressed as 

233U92 → 225Ac89 + 2α

Which means 4 is correct among all