1. Clicker #1 Which is lower in potential energy and more stable?
unburned match or burned match
A) unburned match
B) burned match

2. Clicker #2
Is the boiling of water an endothermic or exothermic process? (The system is underlined.)
A) endothermic
B) exothermic

3. Clicker #3
Is an activated hot pack an endothermic or exothermic process? (The system is underlined.)
A) endothermic
B) exothermic

4. Clicker #4
Is a racquetball frozen by liquid nitrogen an endothermic or exothermic process? (The system is underlined.)
A) endothermic
B) exothermic