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Finding atoms in a sample

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Avogradro's number (6.022 x 10^23 atoms/mol) is a useful number that can be used to calculate a number of different values for compounds/elements. One important value is finding the number of atoms in a specific mass of an element. The solution includes a general step-by-step method of finding the number of atoms in a specific mass of a particular element.

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The given information in a problem of this type will include the mass (usually in grams) of the element and the atomic mass of the element in g/mol. For example, 10 grams of ...

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Confidence Intervals and Sample Size Problems

1) Eight chemical elements do not have isotopes (different forms of the same element having the same atomic number but different atomic weights). A random sample of 30 of the elements that do have isotopes showed a mean number of 19.63 isotopes per element and the population a standard deviation of 18.73.

Estimate the true mean number of isotopes for all elements with isotopes with 90% confidence.

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