60. Silicon has three naturally occurring isotopes (Si-28, Si-29, and Si-30). The mass and natural abundance of Si-28 are 27.9769 u and 92.2%, respectively. The mass and natural abundance of Si-29 are 28.9765 u and 4.67%, respectively. Find the mass and natural abundance of Si-30.

60. Silicon has three naturally occurring isotopes (Si-28, Si-29, and Si-30). The mass and natural abundance of Si-28 are 27.9769 u and 92.2%, respectively. The mass and natural abundance of Si-29 are 28.9765 u and 4.67%, respectively. Find the mass and natural abundance of Si-30.

Chemistry: The Molecular Science

5th Edition

ISBN:9781285199047

Author:John W. Moore, Conrad L. Stanitski

Publisher:John W. Moore, Conrad L. Stanitski

Chapter2: Chemical Compounds

Section: Chapter Questions

Problem 27QRT

See similar textbooks

Similar questions

Average Atomic Weight Part 1: Consider the four identical spheres below, each with a mass of 2.00 g. Calculate the average mass of a sphere in this sample. Part 2: Now consider a sample that consists of four spheres, each with a different mass: blue mass is 2.00 g, red mass is 1.75 g, green mass is 3.00 g, and yellow mass is 1.25 g. a Calculate the average mass of a sphere in this sample. b How does the average mass for a sphere in this sample compare with the average mass of the sample that consisted just of the blue spheres? How can such different samples have their averages turn out the way they did? Part 3: Consider two jars. One jar contains 100 blue spheres, and the other jar contains 25 each of red, blue, green, and yellow colors mixed together. a If you were to remove 50 blue spheres from the jar containing just the blue spheres, what would be the total mass of spheres left in the jar? (Note that the masses of the spheres are given in Part 2.) b If you were to remove 50 spheres from the jar containing the mixture (assume you get a representative distribution of colors), what would be the total mass of spheres left in the jar? c In the case of the mixture of spheres, does the average mass of the spheres necessarily represent the mass of an individual sphere in the sample? d If you had 80.0 grams of spheres from the blue sample, how many spheres would you have? e If you had 60.0 grams of spheres from the mixed-color sample, how many spheres would you have? What assumption did you make about your sample when performing this calculation? Part 4: Consider a sample that consists of three green spheres and one blue sphere. The green mass is 3.00 g, and the blue mass is 1.00 g. a Calculate the fractional abundance of each sphere in the sample. b Use the fractional abundance to calculate the average mass of the spheres in this sample. c How are the ideas developed in this Concept Exploration related to the atomic weights of the elements?
Click on the site (http://openstaxcollege.org/l/16PhetAtomMass) and select the Mix Isotopes tab, hide the Percent Composition and Average Atomic Mass boxes, and then select the element boron. Write the symbols of the isotopes of boron that are shown as naturally occurring in significant amounts. Predict the relative amounts (percentages) of these boron isotopes found in nature. Explain the reasoning behind your choice. Add isotopes to the black box to make a mixture that matches your prediction in (b). You may drag isotopes from their bins or click on More and then move the sliders to the appropriate amounts. Reveal the Percent Composition and Average Atomic Mass boxes. How well does your mixture match with your prediction? If necessary, adjust the isotope amounts to match your prediction. Select Nature’s mix of isotopes and compare it to your prediction. How well does your prediction compare with the naturally occurring mixture? Explain. If necessary, adjust your amounts to make them match Nature’s amounts as closely as possible.
The following chart shows a general decline in abundance with increasing mass among the first 30 elements. The decline continues beyond zinc. Notice that the scale on the vertical axis is logarithmic, that is, it progresses in powers of 10. The abundance of nitrogen, for example, is 1/10,000 (1/104) of the abundance of hydrogen. All abundances are plotted as the number of atoms per 102 atoms of H. (The fact that the abundances of Li, Be, and B, as well as those of the elements near Fe, do not follow the general decline is a consequence of the way that elements are synthesized in stars.) (a) What is the most abundant main group metal? (b) What is the most abundant nonmetal? (c) What is the most abundant metalloid? (d) Which of the transition elements is most abundant? (e) Which halogens are included on this plot, and which is the most abundant?
Click on the site (http://openstaxcollege.org/l/16PhetAtomMass) and select the Mix Isotopes tab, hide the Percent Composition and Average Atomic Mass boxes, and then select the element boron. Write the symbols of the isotopes of boron that are shown as naturally occurring in significant amounts. Predict the relative amounts (percentages) of these boron isotopes found in nature. Explain the reasoning behind your choice. Add isotopes to the black box to make a mixture that matches your prediction in (b). You may drag isotopes from their bins or click on More and then move the sliders to the appropriate amounts. Reveal the Percent Composition and Average Atomic Mass boxes. How well does your mixture match with your prediction? If necessary, adjust the isotope amounts to match your prediction. Select Nature’s mix of isotopes and compare it to your prediction. How well does your prediction compare with the naturally occurring mixture? Explain. If necessary, adjust your amounts to make them match Nature’s amounts as closely as possible. 21. Repeat Exercise 2.20 using an element that has three naturally occurring isotopes.
Neon has three stable isotopes, one with a small abundance. What are the abundances of the other two isotopes? 20Ne, mass = 19.992435 u; percent abundance = ? 21Ne mass = 20.993843 u; percent abundance = 027% 22Ne mass = 21.991383 u: percent abundance = ?
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 average atomic masses of some elements may vary, depending upon the sources of their ores. Naturally occurring boron consists of two isotopes with accurately known masses ( 10B, 10.0129 amu and 11B, 11.0931 amu). The actual atomic mass of boron can vary from 10.807 to 10.8 19, depending on whether the mineral source is from Turkey or the United States. Calculate the percent abundances leading to the two values of the average atomic masses of boron from these two countries.
Early tables of atomic weights (masses) were generated by measuring the mass of a substance that reacts with 1.00 g of oxygen. Given the following data and taking the atomic mass of hydrogen as 1.00, generate a table of relative atomic masses for oxygen, sodium, and magnesium. Element Mass That Combines with 1.00Oxygen Assumed Formula Hydrogen 0.126g HO Sodium 2.875g Nao Magnesium 1.500g Mgo
A mass spectrometer determines isotopic masses to eight or nine significant digits. What limits the atomic mass of carbon to only five significant digits?
The element europium exists in nature as two isotopes: 151Eu has a mass of 150.9196 u and 153Eu has a mass of 152.9209 u. The average atomic mass of europium is 151.96 u. Calculate the relative abundance of the two europium isotopes.
An element consists of 1.40% of an isotope with mass 203.973 u, 24.10% of an isotope with mass 205.9745 u, 22.10% of an isotope with mass 206.9759 u, and 52.40% of an isotope with mass 207.Y766 u. Calculate the average atomic mass, and identify the element.
The atomic masses in die periodic table are relative masses and average masses. Explain.