Each group needs:

• ½ cup tap water
• ½ cup lemon juice
• ½ cup white vinegar
• 3 pieces white chalk (larger chalk pieces with a flat surface, if possible, these are easier for the students to decorate)
• 3 small cups labeled with group names (clear plastic cups work best)
• 3 nails (or other sharp objects that could scratch chalk)
• 3 strips litmus paper
• Acid Rain Worksheet, one per student
• Acid KWL Chart, one per student

For the teacher/instructor:

• waterproof marker
• timer, such as a watch, clock or stopwatch