To draw the Lewis structure of calcium chloride (CaCl2), we need to consider the valence electrons of the constituent atoms. Calcium (Ca) is in Group 2 of the periodic table, so it has 2 valence electrons. Chlorine (Cl) is in Group 17 and has 7 valence electrons.
In calcium chloride, one calcium atom donates its 2 valence electrons to two chlorine atoms. This donation allows calcium to achieve a stable electron configuration similar to the noble gases, while each chlorine atom gains one electron to complete its octet, achieving stability as well.
The Lewis structure can be represented as follows:
- Place the symbol for calcium (Ca) in the center.
- Draw arrows from the calcium atom to each of the chlorine atoms to indicate the transfer of electrons.
- For each chlorine atom, draw 6 dots (representing the remaining valence electrons after gaining one from calcium) around it to signify its complete octet.
Thus, in the Lewis structure of calcium chloride, we illustrate how calcium loses its two valence electrons and forms ionic bonds with two chloride ions:
Cl: Ca Cl:
: +2 :
.. ..
This representation shows how calcium chloride consists of one calcium ion (Ca2+) and two chloride ions (2Cl–). This is how you can visualize the bonding in calcium chloride using Lewis structures.