A student sets up the following equation to convert a measurement. (The ? stands for a number the student is going to calculate.) Fill in the missing part of this equation. (81. 81. Pa mm 2)=? = ? Pa m 2 x10 ロ・ロ

To determine the average mass of a popcorn kernel, you collect the following data: Plot the data with number of kernels on the x-axis and mass on the y-axis. Draw the best straight line using the points on the graph (or do a least- squares or linear regression analysis using a computer program), and then write the equation for the resulting straight line. What is the slope of the line? What does the slope of the line signify about the mass of a popcorn kernel? What is the mass of 20 popcorn kernels? How many kernels are there in a handful of popcorn with a mass of 20.88 g?

This year, like many past years, you begin to feel very sleepy alter eating a large helping of Thanksgiving turkey. Some people attribute this sleepiness to the presence of the amino acid tryptophan in turkey. Tryptophan can be used by the body to produce serotonin, which can calm the brains activity and help to bring on sleep. a. What mass in grams of tryptophan is in a 0.25-lb serving of turkey? (Assume tryptophan accounts for 1.0% of the turkey mass.) b. What mass in grams of tryptophan is in 0.25 quart of milk? (Assume tryptophan accounts for 2.0% of milk by mass and that the density of milk is 1.04 kg/L.)

When a mixture of aluminum powder and iron(III) oxide is ignited, it produces molten iron and aluminum oxide. In an experiment, 5.40 g of aluminum was mixed with 18.50 g of iron(III) oxide. At the end of the reaction, the mixture contained 11.17 g of iron, 10.20 g of aluminum oxide, and an undetermined amount of unreacted iron(III) oxide. No aluminum was left. What is the mass of the iron(III) oxide?