CaS and MgO.
On the periodic table, you can see that these elements are located in either group 1, 2, 6, and 7. Group 1 and 7 both have a singular valence electron with either a negative or positive charge while group 2 and 6 both have two valence electrons.
Calcium, Sulfur, Magnesium, and Oxygen all have two valence electrons. The other choices only have one valence electron.
Hope this helps!
Answer : The correct options are, CaS and MgO.
Explanation :
Ionic compound : These are the compounds in which atoms are bonded through the ionic bond and they are formed by the complete transfer of electrons.
When the atom looses the electron is considered as electropositive atom and the atom gain the electrons is known as electronegative atom.
These bonds are formed between one metal and one non-metal.
KCl : It is an ionic compound in which the a metal (K) react with the non-metal (Cl) and combine with the an ionic bond by the criss-cross method.
NaF : It is an ionic compound in which the a metal (Na) react with the non-metal (F) and combine with the an ionic bond by the criss-cross method.
CaS : It is an ionic compound in which the a metal (Ca) react with the non-metal (S) and combine with the an ionic bond by the criss-cross method.
MgO : It is an ionic compound in which the a metal (Mg) react with the non-metal (O) and combine with the an ionic bond by the criss-cross method.
Hence, the correct options are, CaS and MgO.
