Question #7639c

1 Answer
Dec 1, 2016

#MgCl_2# originated from Magnesium (Mg) and Chlorine (Cl) atoms.

There is one Mg atom and two Cl atoms (since there is a 2 after the Cl) that forms the compound #MgCl_2#.

It works that way because #MgCl_2# is made up of positive #Mg^2+# ions and negative #Cl^-# ions. In order for #Mg^2+# and #Cl^-# to bond together, the 2 from #Mg^2+# moves to the end of Cl so that makes #MgCl_2#.

Therefore, #MgCl_2# contains #Mg# and #Cl# elements and there are 3 atoms altogether.