Science Fair - S1-E1
Continuity mistake: After her teacher walks up, Cassie jumps up excited to pour the chemicals into her volcano to set it off. It cuts to a quick reaction shot of Scott realizing he forgot to give her the baking soda. Then it cuts back to Cassie; suddenly, she is sitting down in a green chair and her teacher's hand is on the back of the chair. Also, her position next to the volcano has changed; note the corner of the board when she's standing then sitting. (00:00:15)