In Problems 41–48, you need to make some assumptions before you estimate your answer. State your assumptions and then calculate the exact answer.

The Genesis space capsule crashed into the Utah desert and Keay Davidson said (in the Chronicle Science Writer), “Shaken NASA officials immediately began the tedious process of recovering the capsule. They hope to salvage the probe’s unique scientific data: roughly a billion billion particles from the deep-space ‘solar wind.’” State the number of particles in scientific notation.