The composition of dry air is approximately 78% nitrogen, 21% oxygen and 1% other gases. What is the partial pressure of oxygen at standard atmospheric pressure (1.00 atm)?

Each of the following compounds contains a metal that can exhibit more than one ionic charge. provide systematic names for each of these compounds. (a) cr(clo3)6 (b) mo(cn)6 (c) cr2(so3)3 (d) v(clo2)2 (e) v(cn)5 (f) os(clo2)4

Suppose the universe were completely empty except for one object-a solid sphere moving through space of 100 km/s. what sort of path would the object be moving in? explain your answer

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.