Bismuth has a density of 9.808 g/cm3 at 25 degrees Celsius. Calculate the number of atoms of Bismuth in a cube with edges of 5.0 cm in length, and calculate the number of moles of Bismuth in the cube.

With the advent of techniques such as scanning tunneling microscopy, it is now possible to write with individual atoms by manipulating and arranging atoms on an atomic surface. a. If an image is prepared by manipulating iron atoms and their total mass is 1.05 1020 g, what number of iron atoms were used? b. If the image is prepared on a platinum surface that is exactly 20 platinum atoms high and 14 platinum atoms wide, what is the mass (grams) of the atomic surface? c. If the atomic surface were changed to ruthenium atoms and the same surface mass as determined in part b is used, what number of ruthenium atoms is needed to construct the surface?

You have a pure sample of apholate, C12H24N9P3, a highly effective commercial insecticide. Calculate the molar mass of apholate. Calculate the mass of N in 100. g apholate. A sample containing 250.0 mg apholate is sprayed on an agricultural field. Calculate the mass of phosphorus in this sample of apholate; express your result in grams. Calculate the number of phosphorus atoms in this sample of apholate.

1. Which of the following hydrocarbons has the highest mass percentage of carbon? methane, CH4 ethane, C2H6 propane, C3H8 butane, C4H10

The age of the universe is unknown, but some conclude from measuring Hubbles constant that the age is about 18 billion years old, which is about four times the age of Earth. If so, calculate the age of the universe in seconds. If you had a sample of carbon with the same number of carbon atoms as there have been seconds since the universe began, determine whether you could measure this sample on a laboratory balance that can detect masses as small as 0.1 mg.

Saccharin, a molecular model of which is shown below, is more than 300 times sweeter than sugar. It was first made in 1807, when it was common practice for chemists to record the taste of any new substances they synthesized. (a) Write the molecular formula for the compound, and draw its structural formula. (S atoms are yellow.) (b) If you ingest 125 mg of saccharin, what amount (moles) of saccharin have you ingested? (c) What mass of sulfur is contained in 125 mg of saccharin?

A compound associated with the odor of garlic on a persons breath has the chemical formula CyH8S and a formula mass of 88.19 amu. What number does y stand for in the chemical formula of the compound?

3.107 As computer processor speeds increase, it is necessary for engineers to increase the number of circuit elements packed into a given area. Individual circuit elements are often connected using very small copper “wires” deposited directly onto the surface of the chip. In some processors, these copper interconnects are about 22 nm wide. How many copper atoms would be in a 1-mm length of such an interconnect, assuming a square cross section? (The density of copper is 8.96 g/cm3.)