More cards in this set

Card 6

Front

what is a collid ?

Back

Preview of the front of card 6

Card 7

Front

what is the special feature of thermochromic and phosphorescent pigments ?

Back

Preview of the front of card 7

Card 8

Front

In the past what was wrong with glow-in-the-dark watch faces ?

Back

Preview of the front of card 8