Me. Belland is setting up a lab that requires a solutions of sodium hydroxide. This chemical comes in solid form and he has the option of large flakes or small pebbles. Which should he use to create his solution and why?

see  below

Explanation:

Neither form of the reagent has any significant effect on the final solution being prepared. The only advantage may be in the flakes in that the dissolution rate could be faster due to higher surface area of the form but that would not greatly affect the outcome of the final preparation. Outside of that, the only other issue would be 'purity' of the reagent but that would be taken into account when determining amounts needed for preparation of the solution.

3 hours because it is a decent distance.

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).