Chapter 2, Problem 2.28E

Two compounds of iron and chlorine, A and B, contain 1.270 g and 1.904 g of chlorine, respectively, for each gram of iron. Show that these amounts are in the ratio 2 : 3. Is this consistent with the law of multiple proportions? Explain.

There are 2.619 1022 atoms in 1.000 g of sodium. Assume that sodium atoms are spheres of radius 1.86 and that they are lined up side by side. How many miles in length is the line of sodium atoms?

During nuclear decay a 238U atom can break apart into a helium-4 atom and one other atom. Assuming that no subatomic particles are destroyed during this decay process, what is the other element produced?

Though the common isotope of aluminum has a mass number of 27, isotopes of aluminum have been isolated (or prepared in nuclear reactors) with mass numbers of 24, 25, 26, 28, 29, and 30. How many neutrons are present in each of these isotopes? Why are they all considered aluminum atoms, even though they differ greatly in mass? Write the atomic symbol for each isotope.

Define the term atomic weight. Why might the values of atomic weights on a planet elsewhere in the universe be different from those on earth?

Argon has three naturally occurring isotopes: 0.3336% 36Ar, 0.063% 38Ar, and 99.60% 40Ar. Estimate the average atomic mass of argon. If the masses of the isotopes are 35.968 u, 37.963 u, and 39.962 u, respectively, calculate the average atomic mass of natural argon.

The following isotopes have applications in medicine. Write their symbols in the form XZA. a. cobalt-60 b. phosphorus-32 c. iodine-131 d. sulfur-35

A single molecule has a mass of 7.31 1023 g. Provide an example of a real molecule that can have this mass. Assume the elements that make up the molecule are made of light isotopes where the number of protons equals the number of neutrons in the nucleus of each element.

See the definition for isobars in Question 15. Consider Cr-54, Fe-54, Fess, and Ni-S8. (a) Which of these are isobars? Which are isotopes? (b) What do Fe-S4 and Fe-58 have in common? (c) Which atoms have the same number of neutrons?