Which statement is true?

rocks do not contain any mineral matter.

most rocks are composed of a single mineral.

most rocks are made up of a mixture of minerals.

Is this a single replacement reaction or there is no

Calculate the number of molecules present in 0.750 mol of mgo.

2pos suppose an object in free fall is dropped from a building. its starting velocity is 0 m/s. ignoring the effects of air resistance, what is the speed (in m/s) of the object after falling 3 seconds? give your answer as a positive decimal without units. answer here