Kick it up a notch?
(When MIT makes statements like “introductory level” I don’t think they have a normal concept of the term. Nonetheless, no harm, no foul. And one of their very best courses with one of the very best professors, Prof. Grossman, is also one of the most generous with texts, discussions… everything but the brain power.)
One of the very best things about MOOCs is the free textbooks (or portions of textbooks) so often included in them. A gazillion years ago, when I was in school, a science textbook averaged $150.
(And science majors rarely have the luxury of getting to buy a used textbook.)
Again, with MOOCs you can poke around. Visit. See what you like. Sometimes you’ll surprise yourself. Even some subjects with work beyond what you feel you could manage in the strictest sense can still be fascinating.
(So don’t be intimidated!) There’s even a regular day quiz cheat sheet. Quiz 1; Question 1:
Thermite reaction:
The thermite reaction, used to weld rails together in the building of railroads, occurs when iron(III) oxide (Fe2O3) reacts with elemental aluminum to produce aluminum oxide (Al2O3) and elemental iron.
(a) Write a balanced equation for this reaction, using any correct set of coefficients. Depict the reaction arrow (⟶) as ‘->’.
And if you’re not too intimidated by it, do yourself a solid –
serene 