Which of the following pairs of solutions produce a precipitate when combined? Cu(NO3)2 and NaCl
Fe(NO3)3 and MgCl2
Cu(NO3)2 and K2CO3
CaCl2 and NaNO3

What term describes technology that operates on an atomic level

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?

Suppose that some of the compound spilled out of the crucible after it was heated. would that cause the percent by mass of water in the compound determined by the experiment to be too low, too high, or unchanged? briefly explain your answer.