What is the atmosphere like in the Cratchit's house? How did Scrooge feel after witnessing the events, and why?

The atmosphere is bubbly, energetic and joyous. We know this because of the quick pace and listing in Stave 3. "Danced around the table", "everyone at once" Scrooge was in grief because he learned that Tiny Tim would die. He starts to develop sympathy and pity.