Consider X + Z -> ? Assuming the following:

The product is an ionic compound.
Element X has 2 valence electrons
Elements Z has 6 valence electrons
Which general formula would be created?
A)ZX
B)Z^2x
C)XZ
D)X2^Z

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

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

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it