5.40 g b determine the number of atoms

Which of the following would be an accurate picture of the earth during the summer time of the northern hemisphere?

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

Give one example of a pure (exact) number and of an estimated (measured) number.