What is the frequency, f, of UV light that has an energy of 5.2 x 10*J? Use the equation, E=hf. Plank's constant, h, is 6.626 x 10-34 ?

Dumbledore decides to gives a surprise demonstration. he starts with a hydrate of na2co3 which has a mass of 4.31 g before heating. after he heats it he finds the mass of the anhydrous compound is found to be 3.22 g. he asks everyone in class to determine the integer x in the hydrate: na2co3·xh2o; you should do this also. round your answer to the nearest integ

Asolution is produced in which water is the solvent and there are four solutes. which of the solutes can dissolve better if the solution is heated?

Explain how to convert from one unit to another in the metric system.