Hey, I need help with this but, can someone simplify?

2 NaHCO3(s) > Na2CO3(aq) + H2O(l) + CO2(g)

Is this reaction balanced? show in a couple of complete sentences why you have chosen your answer. s, aq, l, and g indicate solid, aqueous (water) solution, liquid, and gas respectively.

What about the reaction that forms (synthesizes) carbonic acid?

CO2 + H2O > H2CO3 ? Describe how you know whether this reaction is balanced just as you have for the decomposition reaction above.

Embryos of different species look very similar, which shows that the organisms share a ancestor.

Lab reagent, hypothesis test.a reference solution used as a lab reagent is purported to have a concentration of 5 mg/dl. six samples are taken from this solution and the following concentrations are recorded: (5.32, 4.88, 5.10, 4.73, 5.15, 4.75) mg/dl.these six measurements are assumed to be an srs of all possible measurements from solution.they are also assumed to have a standard deviation of 0.2, a normal distributin, and a mean concentration equal to the true concentration of the solution.carry out a significance test to determine whether these six measurements provide reliable evidence that the true concentration of the solution is actually not 5 mg/dl.

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.