Get started!
Stage 1
Answer 4 questions correctly in a row.
The passage below describes an experiment.

soda with carbon dioxide bubbles
- Sean
wanted to freeze soda to make popsicles. He knew that soda contains carbon dioxide gas, which forms bubbles as it escapes from the liquid. He wondered if the popsicles would freeze more quickly if he removed the carbon dioxide. - Sean
took the lids off three small bottles of soda. He left the lids off overnight so that carbon dioxide could escape from the bottles. He kept the lids on three other bottles to keep the carbon dioxide in. The next morning, Sean placed all six bottles in the freezer. After two hours, he checked whether soda in any of the bottles had frozen.
In this experiment, which were part of a control
group?
the bottles with lids taken off
the bottles with lids kept on
ref_doc_title.
Jumping to stage 1 of 1
Excellent!
Now entering the Challenge Zone—are you ready?
