An element has two isotopes. One isotope has a percent abundance of 75.0% and a mass number of 25 amu. The second isotopes has a percent abundance of25.0% and a mass number of 28 amu. What is the average atomic mass of the element? A.27.3
B.26.5
C.258
D.25.8

Which of the following describes a compound? (hint: carbon and oxygen bo a. a piece of pure carbon, containing only carbon atoms b. oxygen gas surrounding a solid piece of carbon c. a substance made of two oxygen atoms for each carbon atom carbon and oxygen atoms mixed without being bonded together

What is the compound name for the formula [ru(en)2cl2]2+ and [co(en)cl2br]-

Liquid ammonia is produced at high temperatures and under great pressure in a tank by passing a mixture of nitrogen gas and hydrogen gas over an iron catalyst. the reaction is represented by the following equation. n2(g) + 3h2(g) → 2nh3(g) changing all but one experimental condition will affect the amount of ammonia produced. that condition is a) increasing the concentration of both reactants b) changing the temperature within the tank c) decreasing the pressure within the tank. d) increasing only the amount of nitrogen present.