Question

A nucleus _yY^x emits one α and two β particles. The resulting nucleus is ______.

Options

• _yY^{x - 4}

• _{y - 2}Y^{x - 4}

• _{y - 2}Y^{x - 2}

• _yY^{x - 2}

Answer 1

A nucleus _yY^x emits one α and two β particles. The resulting nucleus is _yY^{x - 4}.

Explanation:

Emitting one particle reduces the atomic number by two units and the mass number by four units.
The atomic number increases by one unit when one b particle is emitted.

Therefore the resulting nucleus is \[\ce{_{y - 2 + 2}Y^{x - 4} = _yY^{x - 4}}\]