Answer the following question given this paragraph: Resonance is the use of two or more Lewis structures to represent the covalent bonding in a molecule. One of the valid structures is referred to as a resonance structure. It is now understood that the true structure of a molecule which displays resonance is that of an average or a hybrid of all the resonance structures. In the case of the O 3 molecule, each of the covalent bonds between O atoms is best thought of as being "one and a half" bonds, as opposed to either a pure single bond or a pure double bond. This "half-bond" can be shown as a dotted line in both the Lewis structure and the molecular model (see Figure below ). Q: What is the term for the use of two or more lewis structures to represent the covalent bonding in a molecule? Choices: - reaction - harmony - frequency - resonance A:
resonance

Answer the following question given this paragraph: A: Another example of matter changing color is a penny changing from reddish brown to greenish brown as it becomes tarnished. The color change indicates that a new chemical substance has been produced. Copper on the surface of the penny has combined with oxygen in the air to produce a different substance called copper oxide. Q: What substance is created when a copper turns from reddish brown to greenish brown? Choices: - rust - copper alloy - iron oxide - copper oxide A:
copper oxide

Answer the following question given this paragraph: The table salt pictured in the Figure below contains two elements that are so reactive they are rarely found alone in nature. Instead, they undergo chemical reactions with other elements and form compounds. Table salt is the compound named sodium chloride (NaCl). It forms when an atom of sodium (Na) gives up an electron and an atom of chlorine (Cl) accepts it. When this happens, sodium becomes a positively charged ion (Na + ), and chlorine becomes a negatively charged ion (Cl - ). The two ions are attracted to each and join a matrix of interlocking sodium and chloride ions, forming a crystal of salt. Q: Another name for table salt is? Choices: - hydrogen chloride - carbon chloride - dioxide chloride - sodium chloride A:
sodium chloride