PHET is a great resource that I have shared a bunch over the years. Recently, I was looking at the site when I noticed that its activity search tool now includes a filter for remote activity. With this search tool you can identify remote instructions and lesson plans designed for learning. You can combine the remote search filter with any other topic, level, and language search filter. Watch this short video to see how it works.
More about PhET
In the following video I have shown you how to incorporate PhET science and math simulations on your Google site. Those of you who watch the video will also notice that the simulations can also be shared directly through Google Classroom integration.