<span>Chlorine has 17 electrons in it natural state but it gains an electron and becomes an anion with 18 electrons. </span>
Potassium (K) has 19 electrons in its natural state. It loses an electron and becomes K+ and then is left with 18 <span>electrons .
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The atomic number of calcium is 20 i.e. Ca has 20 electrons.It Loses 2 electrons and becomes Ca++ and has 18 electrons.
