Suppose you are asked to find the area of a rectangle that is 2.1-cm wide by 5.6-cm long. your calculator answer would be 11.76 cm2 . now suppose you are asked to enter the answer to two significant figures. (note that if you do not round your answer to two significant figures, your answer will fall outside of the grading tolerance and be graded as incorrect.)
enter your answer to two significant figures and include the appropriate units.

Write a brief passage describing a neutral atom of nitrogen-14 (n-14). describe the number of protons, neutrons, and electrons in the atom, where each type of particle is located, and how the terms atomic number, mass number, and atomic mass are related to the particles. use the periodic table to you. 14 protons and eletrons since its a neutral atom

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

Calculate - analysis of compound composed of iron and oxygen yields 174.86 of fe and 75.14g of o. what is the empirical formula for this compound?