"The National Geographic Cool Reaction Chemistry Kit has everything your children need to conduct five amazing experiments. They'll make messages appear and disappear, create fizzy, bubbling reactions, and more! A detailed experiment guide takes you step-by-step through each experiment and includes insight into the pH science and chemical reactions that make this kit so much fun! Create fizzy and color changing creations Hide and reveal messages For ages 8 and up 4 pieces of pH paper3 cotton balls 3 cotton balls3 experiment cups 3 experiment cups2 measuring scoops 2 measuring scoopsSodium bicarbonate Sodium bicarbonateCitric acid" "Weight : 1.37 kg Dimensions : 22 × 8 × 30 cm Age：More than 8 years old"