What number of moles represents 2.0 × 1022 atoms of nickel?

What number of atoms of nitrogen are present in 1.00 g of each of the compounds in Exercise 51?

Given that the density of argon is 1.78 g/L under standard conditions of temperature and pressure, how many argon atoms are present in a room with dimensions 4.0 m 5.0 m 2.4 m that is filled with pure argon under these conditions of temperature and pressure?

An element X bas five major isotopes, which are listed below along with their abundances. What is the element? Isotope Percent Natural Abundance Mass (u) 46x 8.00% 45.95232 47x 7.30% 46.951764 48x 73.80% 47.947947 49x 5.50% 48.947841 50x 5.40% 49.944792

The compound As2I4 is synthesized by reaction of arsenic metal with arsenic triiodide. If a solid cubic block of arsenic (d = 5.72 g/cm3) that is 3.00 cm on edge is allowed to react with 1.01 1024 molecules of arsenic triiodide, what mass of As2I4 can be prepared? If the percent yield of As2I4 was 75.6%, what mass of As2I4 was actually isolated?

Fulgurites are the products of the melting that occurs when lightning strikes the earth. Microscopic examination of a sand fulgurite shows that it is a globule with variable composition that contains some grains of the definite chemical composition Fe 46.01%, Si 53.99%. Determine the empirical formula of these grains.

Boron consists of two isotopes, 10B and 11B. Chlorine also has two isotopes, 35Cl and 37Cl. Consider the mass spectrum of BC13. How many peaks would be present, and what approximate mass would each peak correspond to in the BCl3 mass spectrum?

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?

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Calculate the number of atoms of silicon (Si) in 415 cm3of the colorless gas disilane at 0°C and atmospheric pressure, where its density is 0.00278 g cm-3 . The molecular formula of disilane is Si2H6.