IME, school felt slow for about a quarter of my class and that was with the pre-Reagan budgets.
I hear they don't teach a lot of subjects we had and that critical thinking is not encouraged at least in some states.
With a spool of wirewrap wire and a couple of bar magnets you can demonstrate Faraday-Lenz but with an Arduino, a linear Hall sensor, and some ask-for-easy code you can probe the field and see what drives the demonstration down to small decimals.
With an Arduino, wire, caps and a conductive surface you can sense electric fields like your own. That's how capacitive touch buttons work. The question is will you pay $10 or use some wire, 2 caps, a paperclip and a gum wrapper instead? Use alligator clip leads if you don't want to solder or use a breadboard.
Look on eBay for cheap small alligator clips, pennies each for 50+. Want to connect a wire to a resistor? Hold or twist them together and clip them. Done. Use the money you save to get a good meter and maybe a logic probe. :)
The 11 year old might not be ready to code on day one but if the 11 year old wants then the 12 year old may be good at it. He's coming into his peak learning years.