Answer:
Calcium (Ca) is an element with an atomic number of 20, meaning it has 20 protons in its nucleus. The number of protons determines the element's identity. In its neutral state, calcium has an equal number of protons and electrons, giving it a charge of zero.
When calcium bonds with other atoms, it tends to lose two electrons to achieve a stable electron configuration. By losing these two electrons, calcium achieves a full outer electron shell, similar to the noble gas argon. This process results in calcium having a positive charge of +2.
For example, when calcium reacts with chlorine (Cl), it loses two electrons to form calcium chloride (CaCl2). The chlorine atoms gain these electrons, resulting in the formation of chloride ions (Cl-) with a charge of -1 each. The overall compound, calcium chloride, is electrically neutral.
On the other hand, Francium (Fr) is an element with an atomic number of 87. It is an alkali metal and belongs to Group 1 of the periodic table. In its neutral state, francium has an equal number of protons and electrons, resulting in a charge of zero.
Similar to other alkali metals, francium tends to lose one electron to achieve a stable electron configuration. By losing this electron, francium achieves a full outer electron shell, similar to the noble gas radon. This process results in francium having a positive charge of +1.
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