5. An element has two stable isotopes. One of the isotopes has a mass of 11.0093 amu and its natural abundance percentage is 81.07%. The weighted atomic mass for the element is 10.8206 amu. What is the atomic mass for the other isotope? Clearly show your work and place the final number in the box with the correct unit and significant figures. 100- 8107=15

Here are three fictitious elements and a molecular view of the atoms that compose them. The molar mass of the middle element, (b), is 25 grams per dozen (g/doz). (The atoms of these fictitious elements are much larger than ordinary atoms.) Based on the size of the atoms, do you expect the atomic masses of elements (a) and (c) to be greater than or less than (b)? How many atoms are present in 175 g of element (b)?

Neon is an inert gas with three stable isotopes. It is used in gas lasers and in advertising signs. Its isotopes and their abundances are: Ne-20 19.9924 amu 90.51% Ne-21 20.9938 amu 0.27% Ne-22 21.9914 amu 9.22% What is the average atomic mass of neon?

Gather any two of the following items, measure their dimensions, and calculate the number of atoms present in the item. a. a copper penny (pre-1983), density of copper = 8.96g/cm3 b. a nickel (assume that the nickel is pure nickel, Ni), density of nickel = 8.90g/cm3 c. a graphite pencil lead (pure carbon), density of carbon = 2.62g/cm3 d. a helium balloon (assume that the balloon is approximately spherical; the volume of a sphere is V=(43)r3, where r is the radius), density of helium gas = 0.0899 g/L

The CRC Handbook, a large reference book of chemical and physical data, lists two isotopes of rubidium (Z=37). The atomic mass of 72.15 of rubidium atoms is 84.9118u. Through a typographical oversight, the atomic mass of the second isotope is not printed. Calculate that atomic mass.

Indium oxide contains 4.784 g of indium for every 1.000 g of oxygen. In 1869, when Mendeleev first presented his version of the periodic table, he proposed the formula In2O3 for indium oxide. Before that time it was thought that the formula was InO. What values for the atomic mass of indium are obtained using these two formulas? Assume that oxygen has an atomic mass of 16.00.

A gaseous binary compound has a vapor density that is 1.94 times that of oxygen at the same temperature and pressure. When 1.39 g of the gas is burned in an excess of oxygen, 1.21 g water is formed, removing all the hydrogen originally present. (a) Estimate the molecular mass of the gaseous compound. (b) How many hydrogen atoms are there in a molecule of the compound? (c) What is the maximum possible value of the atomic mass of the second element in the compound? (d) Are other values possible for the atomic mass of the second element? Use a table of atomic masses to identify the element that best fits the data. (e) What is the molecular formula of the compound?

Which of the following are isotopes of element X, the atomic number for which is 9: 919X, 920X, 189X, and 921X?

A mass spectrometer determines isotopic masses to eight or nine significant digits. What limits the atomic mass of carbon to only five significant digits?

Average atomic masses listed by JUPAC are based on a study of experimental results. Bromine has two isotopes 79Br and 81Br, whose masses (78.9 183 and 80.9 163 amu) and abundances (50.69% and 49.3 1%) were determined in earlier experiments. Calculate the average atomic mass of bromine based on these experiments.