Chemical Relationships Chemical Bonding: Ionic and covalent bonds and polarity by Anthony Carpi, Ph.D., Adrian Dingle, B.Sc. Reading Quiz Teach with this Which of the following terms would best classify a sample of pure sodium chloride? An element A highly reactive metal A poisonous gas A compound Linus Pauling is famous for proposing the idea of valence octets. proposing that ionic and covalent bonds are at opposite ends of a chemical bonding spectrum. devising dot diagrams to represent the electron configuration of atoms. discovering that there are multiple covalent bonds between some atoms. The three dots in the Lewis dot diagram for boron indicate that it can bond with three other atoms. can only form triple covalent bonds. has three valence electrons. scores a 3 on Pauling's electronegativity scale. Which statement is true of covalent bonds? No matter the element, there is the same bond length between neighboring atoms. Valence electrons must be shared equally between atoms in order to achieve stability. Covalent bonds form when the nuclei of two atoms attract each other. Atoms find the ideal separation distance where electrostatics forces are reduced to a minimum. If a covalent bond were to be formed between a nitrogen atom (electronegativity 3.0) and an oxygen atom (electronegativity 3.5), which of the following statements would best describe such a bond? Non-polar covalent Polar covalent where the oxygen atom carried the partial negative charge Polar covalent where the nitrogen atom carried the partial negative charge Polar covalent where the oxygen atom carried the partial positive charge How many electrons are being shared between the two carbon atoms in the compound ethyne? Ethyne has the Lewis structure: H−C≡C−H 1 2 3 6 Which of the following molecules would one expect to have a non-polar covalent bond? HCl F2 HF ClF What feature of water molecules enables ionic substance to dissolve in water? The water molecules have a certain shape that allows them to surround the ions in solution. The water molecules react with the ions. The water molecules are sticky and can adhere to the ions. The water molecules are polar and are attracted to the positive and negative ions, surrounding them. Score Quiz