1 - Ada Twist, Scientist is the third book in Andrea Beaty and David Roberts' awesome, best-selling STEAM-inspired series, kicked off with Rosie Revere, Engineer and continued with Iggy Peck, Architect. Like the other books, it is a charming characterization of a growth mindset in a young child, told in clever, snappy rhyme, and brilliantly illustrated.
2- Learning Resources Science Lab Activity Set - This set is great for young kids. It comes with set of experiments that can be completed with common household items like baking soda, vinegar, lemon juice, pennies, etc. The experiments are simple and could easily be compiled and completed without the kit, but my kids love the official scientist feeling that comes with the lab goggles and beakers ; )
3 - Awesome Science Experiments For Kids - This book skews a little older, but the older end of the picture book age range (5-8 year olds) could complete these 100 experiments and projects with adult help. The experiments are fun and the book explains the why's and how's in a clear, engaging way.
Not pictured - Educational Insights My First Microscope would be a good option to pair with this book for a slightly older child than the Learning Resources set is aimed at.