What are alpha particles ? In the reaction `""_(z)X^(A) rarr Y + alpha`-particle, give the atomic number and mass number of Y.

Explanation

To solve the problem, we need to understand the concept of alpha particles and how they affect the atomic and mass numbers in a nuclear reaction. Let's break it down step by step.

### Step 1: Understanding Alpha Particles
Alpha particles are composed of 2 protons and 2 neutrons. They are essentially the nucleus of a helium atom (He). When an atom undergoes alpha decay, it emits an alpha particle.

**Hint:** Remember that an alpha particle is equivalent to a helium nucleus.

### Step 2: Analyzing the Reaction
...