An online list of STEM / STEAM Databases and Resources, including STEM / STEAM activities and STEM / STEAM experiments.
Below is a search across all of the resources for activities:
How To Smile: http://howtosmile.org
The Center for Advancement of Informal Science: http://www.informalscience.org
National Informal STEM Education Network: https://www.nisenet.org/educational-resources
STARnet Libraries: http://clearinghouse.starnetlibraries.org/index.php
CLEAN: http://cleanet.org/clean/educational_resources/index.html
MADE Clear: http://madeclear.thinkport.org/#resources.html
COSEE: http://www.cosee.net/resources/
Teach Engineering: http://www.teachengineering.org
NASA Wavelength: https://science.nasa.gov/learners/wavelength
Museums for Digital Learning: https://museumsfordigitallearning.org
Digital Empowerment Project: https://museum-hub.org/about-the-hub/