1. based on the information from the movie, what can you conclude about the most common chemical compound on earth?

a. it's oxygen
b. it's hydrogen gas
c. it's carbon dioxide
d. it's water

2. what is true of a compound?

a. it does not always retain the properties of the substances that make it up
b. it must have water as one of its components
c. it requires heat energy to make
d. it requires electrical energy to make

Describe the forces both attractive and repulsive that occur as two atoms move closer together.

Phosphoric acid is a triprotic acid ( =6.9×10−3 , =6.2×10−8 , and =4.8×10−13 ). to find the ph of a buffer composed of h2po−4(aq) and hpo2−4(aq) , which p value should be used in the henderson–hasselbalch equation? p k a1 = 2.16 p k a2 = 7.21 p k a3 = 12.32 calculate the ph of a buffer solution obtained by dissolving 18.0 18.0 g of kh2po4(s) kh 2 po 4 ( s ) and 33.0 33.0 g of na2hpo4(s) na 2 hpo 4 ( s ) in water and then diluting to 1.00 l.

Select the correct answer from each drop-down menu. to make a table of the elements, dmitri mendeleev sorted the elements according to their . he then split the list of elements into several columns so that elements beside each other had similar .