Refer to a periodic table and tell how many helium atoms (he) would be needed to
get close to the same mass as an average oxygen atom (o).
a. six
b. four
c. twelve
d. one-fourth

The three types is stress that act on earths rocks are compression, tension, and

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. in the first step, nitrogen and hydrogen react to form ammonia: (g) (g) (g) in the second step, ammonia and oxygen react to form nitric acid and water: (g) (g) (g) (g) calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .

Calculate the ph of a .10m nh4cl solution. the kb value for nh3 is 1.8×10^-5