A negative ion of an atom of element X has 18 electrons and 16 protons. Calculate the number of electrons and protons in its corresponding atom. Also calculate the number of neutrons, if the mass number is 2 units more than double the number of protons.

Explanation

To solve the problem step by step, let's break it down into manageable parts.

### Step 1: Identify the number of protons and electrons in the negative ion
- We are given that the negative ion of element X has 18 electrons and 16 protons.

### Step 2: Determine the number of protons and electrons in the corresponding atom
- In a neutral atom, the number of protons equals the number of electrons.
- Since the negative ion has gained 2 extra electrons (18 - 16 = 2), the corresponding neutral atom will have:
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