Answer the following key sets of questions in the discussion forum.

1. As it relates to long-term assets, what is goodwill?
2. What is meant by a transaction lacking commercial substance? How does the presence (or lack) of commercial substance inform the accounting for an exchange of long-term assets?
3. How are research and development (R&D) costs treated on the balance sheet?
4. What is the conceptual difference between depreciation and an impairment? How would a company go about recording each for a factory that it owns?