What do the superscripts in an electron configuration represent?

If equal masses of the listed metals were collected , which would have a greatest volume ? a. aluminum 2.70,b.zinc7.14,c.copper 8.92,d.lead 11.34

An experimental procedure requires a 10 ml of acid to be dissolved

The reactions shown here can be combined to make the overall reaction c(s) + h2o(g) ⇌ co(g) + h2(g) by reversing some and/or dividing all the coefficients by a number. a. c(s) + o2(g) → co2(g) k=1.363×10^69 b. 2 h2(g) + o2(g) → 2 h2o(g) k=1.389×10^80 c. 2co(g) + o2 (g) → 2 co2(g) k=1.477×10^90