Question

In 4-5 sentences, compare the bonding characteristics of chlorine (atomic number 17, period 3, group 17) with those of magnesium (atomic number 12, period 3, group 2). Discuss how their positions in the periodic table influence their ability to form bonds, including the types of bonds they are likely to form and the resulting properties of the compounds they create. Please make your answer simple, coherent, and intended for 9th grade.

Answer 1

Chlorine (period 3, group 17) has seven valence electrons and is a nonmetal, so it tends to gain one electron to become Cl− and commonly forms covalent bonds (like Cl2) with other nonmetals or ionic bonds with metals (like NaCl). Magnesium (period 3, group 2) has two valence electrons and is a metal, so it tends to lose those electrons to become Mg2+ and form ionic compounds (like MgCl2) and metallic bonds in the elemental metal. Because chlorine is highly electronegative it pulls electrons toward itself, while magnesium gives up electrons easily; this difference explains why magnesium and chlorine readily form an ionic salt together. Ionic compounds (from metals + nonmetals) are usually crystalline with high melting points and conduct electricity when molten or dissolved, whereas simple covalent molecules often have lower melting/boiling points.