MediumChemistryHigh School (11–12)Structure of the Atom › Isotopes and Isobars Structure of the Atom › Subatomic Particles and Atomic ModelsNumericalBoard Exam AP A-Level IB

Rubidium has two isotopes, ⁸⁵Rb and ⁸⁷Rb…

Contributed by StemPy Lab

Try it on paper first. A hint, the key idea and the worked solution are here when you need them.

Rubidium has two isotopes, ${}^{85}\text{Rb}$ and ${}^{87}\text{Rb}$ . Its average atomic mass is $85.47\ \text{u}$ . Taking each mass as its mass number, find the percentage of each isotope.

Need a reminder? The key ideaShow

$Z$ counts protons, $A$ protons plus neutrons, and $N = A - Z$ . Isotopes share $Z$ , isobars share $A$ , isotones share $N$ . Average atomic mass $=$ the sum of (mass $\times$ share). In a mass spectrometer, $r = \dfrac{1}{B}\sqrt{\dfrac{2mV}{q}}$ , so $r \propto \sqrt{m}$ .

The worked solution

Have you tried it?

Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.

← All Problems

← Singly charged ions of boron-10 and boron-11 are accelerated through the same voltage and enter the…A sodium lamp gives out yellow light of wavelength 589 nm… →

More onStructure of the Atom › Isotopes and Isobars Structure of the Atom › Subatomic Particles and Atomic Models

Discussion (0)

Loading…