# chemistry

posted by .

This is a lengthy problem, but I really don't understand it. Any assistance given would be greatly appreciated.

An analysis was done on a rock sample to determine its rubidium content. The rubidium content of a portion of rock weighing .350g was extracted, and to the extracted sample was added an additional 29.45 micrograms of rubidium-87. the mass spectrum of this spiked sample showed a rubidium-87 peak that was 1.12 times as high as the peak of rubidium-85. assuming that the two isotopes react identically, what is the rubidium content of the rock (expressed in parts per million by mass)?

rubidium-87 atomic mass=86.909u
% natural abundance=27.83% of all rubidium
rubidium-85 atomic mass=84.912u
% natural abundance=72.17% of all rubidium

I am particularly confused by the peaks aspect of this problem. Does that mean like something with mass or what? Please help. Thanks.

## Similar Questions

1. ### chemistry asap!

I'm having trouble solving this percentage concentration problem: A student wants to make 5.00% solution of rubidium chloride using 0.377g of the substance. What mass of water will be needed to make the solution?
2. ### Calculating Average Atomic Mass

Rubidium has 2 common isotopes, Rb 85 and Rb 87. If the abudance of Rb 85 is 70 percent and the abundance of Rb 87 is 30 percent, what is the average atmoic mass of rubidium?
3. ### Science HELP 2nd question

A sample originally contained 2.5 g of rubidium 87 now contains 1.25 g. The half life of rubidium - 87 is 6 x 10 ( to the 10th) years. How old is the sample?
4. ### com 140 Contemporary Business Communication

Characteristics of Interpersonal Communication Im having a little problem with this assignment not really sure what to do. There are 2 section on ths assignment 1 is Instructor message and 2 is Class mate message. In each section ther …
5. ### chemistry

Enter the formula and state of the major species that result when a few grams (about 0.01 mol) of each substance is added to 100 mL of water. When appropriate use water to form species such as the hydronium ion. Separate multiple species …
6. ### chemistry

rubidium is the fourth element in group 1. predict the following properties of rubidium and its compunds: A. appearence B. hardness C. reaction with water D. appearance and solubility of rubidium chloride E. electrical conductivity
7. ### Chemistry

A laser emitting light with a wavelength of 480 nm is directed toward the surface of rubidium metal. The work function for rubidium metal is 2.16 eV (1 eV = 1.602 x 10-19 J)
8. ### chemistry

Estimate the change in energy when solid rubidium reacts with gaseous diatomic chlorine molecules. Express your answer in units of kJ/mole. Do not refer to the periodic table to solve this problem. The following data may be useful …
9. ### Chemistry

Estimate the change in energy when solid rubidium reacts with gaseous diatomic chlorine molecules. Express your answer in units of kJ/mole. Do not refer to the periodic table to solve this problem. The following data may be useful …
10. ### Chemistry

The element rubidium has bcc packing with a body-centered cubic unit cell. The density of Rb is 1530 kg/m3. Calculate the volume (L) of the unit cell of rubidium. Molar mass of Rb=85.468. Since it is bcc, it would have 2 atoms/unit …

More Similar Questions