You synthesize a sample of a superheavy element with an atomic number of 180.In a mass spectrometer,you find two peaks at 5.08113 $\times$ 10^-25 kg and 5.11434 $\times$10^-25 kg,with the former appearing to be about 2.500 times larger than the latter.What is the approximate average atomic mass of this element in amu? (1 amu = 1.6605 $\times$10^-27 kg)

Question

Quizplus · Accepted Answer

We are given two peaks in a mass spectrometer at masses of 5.08113 × 10⁻⁹ kg and 5.11434 × 10⁻⁹ kg, respectively. We are also told that the first peak is about 2.5 times larger than the second peak. Let's call the mass of the first peak x kg. Then we can write:

2.5(x/1.6605 × 10⁻²⁷) = (5.11434/1.6605 × 10⁻²⁷)

Solving for x, we get:

x = 8.127 × 10⁻²⁷ kg

The average atomic mass of the superheavy element is then:

[(1)(1.6605 × 10⁻²⁷) + (180)(8.127 × 10⁻²⁷)]/181

= 4.555 × 10⁻²⁵ kg

= 306.6 amu (to three significant figures)

Therefore, the best answer is C.

You Synthesize a Sample of a Superheavy Element with an Atomic