Question

The ion with 86 electrons, 142 neutrons, and a 4+ charge

Answer 1

$\qquad\qquad\huge\underline{{\sf Answer}}♨$

The ion had 4+ charge when it had 86 electrons, so it should have no charge on it if there are 4 more electrons and the atom will be neutral.

And since we know that number of electrons in a neutral atom is equal to Atomic Number of that atom.

So, at neutral phase, it had 86 + 4 = 90 electrons

hence, our required atom is : Thorium

And it's ion will be ~$\sf Th^{4+}$

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