An alkaline earth metal is radioactive. It and its daughter element decay by emitting 3 `alpha`- particles in succession. In what group should the resulting element be formed?

Explanation

To solve the problem step by step, we will analyze the decay of the alkaline earth metal and its daughter elements as they emit alpha particles.

### Step 1: Identify the Initial Element
The question states that we have a radioactive alkaline earth metal. Alkaline earth metals are found in Group 2 of the periodic table. Let's denote this element as \( X \).

### Step 2: Understand Alpha Decay
Alpha decay involves the emission of an alpha particle, which is equivalent to a helium nucleus. An alpha particle has:
- **2 protons**
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