A sample of silicon rejected for use in an electronic circuit has an impurity of boron at a level of 3 parts per trillion.What is the fraction of boron atoms in the silicon sample as written in scientific notation? A)3 x 10^-9 B)3 x 10⁹ C)3 x 10^-12 D)3 x 10⁶

Question

Quizplus · Accepted Answer

To convert parts per trillion to a fraction, we divide by 1 trillion (10^12). Therefore, the fraction of boron atoms in the silicon sample is 3/10^12 which can be written in scientific notation as 3 x 10^-12. However, the question asks for the fraction of boron atoms in the sample, not the concentration of boron atoms. Since there is only one atom per particle, the fraction of boron atoms is the same as the concentration, which is 3 x 10^-12. Choice A is the only option that matches this answer.

A Sample of Silicon Rejected for Use in an Electronic