In the next steps, you will see several snapshots taken at different times using the hydrogen burning model. Based on how the molecules and chemical bonds change, choose four pictures to show how the burning of hydrogen gas molecules happens in four steps.

Choose one picture for each step according to the instructions as below. After you've chosen your picture, please submit it for anonymous sharing. After you submit an answer, you'll be able to see a histogram of your classmates' answers after your teacher releases them: You'll see the histogram in a pop-up window that will appear after you click on a Results button.

Here's what you'll do for each of the frames in the next steps:
Frame 1: Choose a picture showing what the molecules look like before the reaction starts.
Frames 2 & 3: Choose pictures showing how the molecules and chemical bonds change during the reaction. Arrange the pictures in the right order.
Frame 4: Choose a picture showing what the molecules look like after the reaction.

Remember that the chemical reaction equation is:

Frame 1 before the reaction

Frame 2 right after the reaction starts

Frame 3 later during the reaction

Frame 4 after the reaction