Batteries - Students are familiar with batteries because all of the devices they care about (their cell phones, laptops, video game controllers, etc) requires them, but what makes them work? I use this activity to help the students learn about batteries and DC power. I use a video on youtube to introduce the topic; while the students are watching the video, they are filling out a video worksheet. After the video is finished, we discuss what they learned. Finally, I have the students read a 6 page article and fill out another worksheet. I recommend using Google forms for the worksheets, but if you prefer to do it with paper I have a document of the questions attached as well.
This activity is perfect for a day when you want the students to do independent work or need a quick sub plan.