Identify each pair of elements as likely to participate in ionic bonding when bonded together. Use your periodic table. 1. Sodium & Chlorin (NaCI) :
2. Carbon & Oxygen (CO2):
3. Hydrogen & oxygen (H2o)
4. Iron & oxygen (Fe2o3):
5. Magnesium & Sulfur (MgS):

1) NaCl, 5)MgS

Explanation:

What makes something an Ionic Bond:

For 1) Na has a charge of 1+ and Cl has a charge of 1-. They both come together to form table salt. Their electronegativity is also larger than 2.0. Also Na is a metal and Cl ion is a nonmetal.

For 2) C and O are both nonmetals and are covalent bonds

For 3) Water is a polar covalent molecule because there is a electronegativity difference between H and O, but not great. H and O are also nonmetals.

For 4) While Fe is a metal and O is a nonmetal, their electronegativity difference is not greater than 2.0. This makes it polar covalent.

For 5) Mg is a metal and S is a nonmetal. They have a large electronegativity difference. Also Mg has a charge of 2+ while S has a charge of 2-.