Chemistry Periodic Table Trivia Quiz

The bonding in KCl is different from the bonding in molecules A, B, and C because KCl is an ionic compound, while molecules A, B, and C are covalent compounds. In KCl, there is a transfer of electrons from the potassium atom to the chlorine atom, resulting in the formation of ions. On the other hand, in molecules A, B, and C, the atoms within the molecules share electrons to form covalent bonds. The difference in bonding is due to the difference in electronegativity between the atoms involved in the bonding.

The bonding in magnesium oxide (MgO) and barium chloride (BaCl2) is similar because both compounds have the same number of valence electrons. Magnesium has 2 valence electrons, while oxygen has 6 valence electrons. Barium has 2 valence electrons, while chlorine has 7 valence electrons. In both cases, the compounds form ionic bonds by transferring electrons. Magnesium donates its 2 valence electrons to oxygen, forming Mg2+ and O2- ions, which attract each other due to opposite charges. Similarly, barium donates its 2 valence electrons to two chlorine atoms, forming Ba2+ and 2Cl- ions, which also attract each other. Therefore, the bonding in both compounds is similar due to the same number of valence electrons.

NH3 has stronger intermolecular forces of attraction than Cl2 because it is an asymmetrical molecule. Asymmetrical molecules have a dipole moment, which means there is an uneven distribution of charge within the molecule. In NH3, the nitrogen atom is more electronegative than the hydrogen atoms, causing a partial negative charge on the nitrogen and partial positive charges on the hydrogens. This creates a dipole moment, allowing for stronger attractions between NH3 molecules through dipole-dipole interactions. In contrast, Cl2 is a symmetrical molecule, with equal electronegativity between the chlorine atoms, resulting in no dipole moment and weaker intermolecular forces of attraction.

CCl4 is classified as a nonpolar molecule because the electrons in the molecule are shared evenly between the carbon atom and the four chlorine atoms. This means that there is no separation of charge within the molecule, resulting in a symmetrical distribution of electron density. As a result, there are no partial positive or negative charges on the atoms, making CCl4 nonpolar.

The correct answer is HCl: polar covalent. This is because HCl is a diatomic molecule composed of a hydrogen atom bonded to a chlorine atom. Chlorine is more electronegative than hydrogen, meaning it attracts the shared electrons in the bond more strongly. As a result, the electrons spend more time closer to the chlorine atom, creating a partial negative charge on the chlorine and a partial positive charge on the hydrogen. This unequal sharing of electrons creates a polar covalent bond in HCl.

Covalent bonding is the correct answer because molecular substances are made up of molecules, which are formed when atoms share electrons. In covalent bonding, atoms share electrons in order to achieve a stable electron configuration. This type of bonding is found in all molecular substances because they are composed of nonmetal atoms that tend to form covalent bonds rather than gaining or losing electrons.