How much of a 500g sample of potassium-42 is left after 37.2 hours if the half-life of potassium-42 is 12.4 hours.

Nitric oxide (no) can be formed from nitrogen, hydrogen and oxygen in two steps. in the first step, nitrogen and hydrogen react to form ammonia: n2(g) + 2 h_2(g) rightarrow 2 nh_3 (g) delta h = -92. kj in the second step, ammonia and oxygen react to form nitric oxide and water: 4 nh_3(g) + 5 o_2(g) rightarrow 4no(g) + 6 h_2o(g) delta h = -905. kj calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .

Agas occupies 475 cm^3 at 313k. find its volume at 367k. you must show all of your work to receive credit. be sure to identify which of the gas laws you will be using

The mass of a neutron is equal to the mass of a proton plus the mass of an electron. true or false false true