2 attempts left Check my work Be sure to answer all parts. Write the formula for the ionic compound formed from the gold(III) cation (Au³+) and each anion: (a) CO3; (b) NO₂ (a) (b)

2-98 Explain how the ionization energy of atoms changes when proceeding down a group of the Periodic Table and explain why this change occurs.

3-58 In Section 2-3B, we saw that there are seven diatomic elements. (a) Draw Lewis structures for each of these diatomic elements. (b) Which diatomic elements are gases at room temperature? Which are liquids? Which are solids?

3-78 Nitrous oxide, N20, laughing gas, is a colorless, nontoxic, tasteless, and odorless gas. It is used as an inhalation anesthetic in dental and other surgeries. Because nitrous oxide is soluble in vegetable oils (fats), it is used commercially as a propellant in whipped toppings Nitrous oxide dissolves in fats. The gas is added under pressure to cans of whipped topping. When the valve is opened, the gas expands, thus expanding (whipping) the topping and forcing it out of the can. (a) How many valence electrons are present in a molecule of N20? (b) Write two equivalent contributing structures for this molecule. The connectivity in nitrous oxide is NNO. (c) Explain why the following is not an acceptable contributing structure: