I need help on my chemistry quiz

If the element whose electric configuration ends in the d sublevel, the element is calssified as? a.inner transition b.noble gases c.representative d. transition

Sulfur dioxide and oxygen react to form sulfur trioxide during one of the key steps in sulfuric acid synthesis. an industrial chemist studying this reaction fills a 25.0l tank with 4.5 mol of sulfur dioxide gas and 4.5 mol of oxygen gas at 30.°c. he then raises the temperature, and when the mixture has come to equilibrium measures the amount of sulfur trioxide gas to be 1.4 mol. calculate the concentration equilibrium constant for the reaction of sulfur dioxide and oxygen at the final temperature of the mixture. round your answer to 2 significant digits.

Consider the four elements above. which one of these elements will combine with oxygen in a 1: 1 ratio?