A radioactive nucleus undergoes a series of deacy according to the scheme.
`Aoverset(alpha)rarrA_(1)overset(beta^(-))rarrA_(2)overset(alpha)rarrA_(3)overset(gamma)rarrA_(4)`
If the mass number and atomic number of `A` are `180` and `72` respectively, what are these numbers for `A_(4)`.

Explanation

To solve the problem step by step, we will analyze each decay process based on the given information about the radioactive nucleus A.

### Step 1: Identify the initial values
- The mass number (A) of nucleus A is given as 180.
- The atomic number (Z) of nucleus A is given as 72.

### Step 2: First decay (Alpha decay)
- In alpha decay, the mass number decreases by 4 and the atomic number decreases by 2.
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