The Physics
Hypertextbook
Opus in profectus

# The Atomic Nature of Matter

## Practice

### practice problem 1

Verify the following claims about the mole.
1. A mole of dollar bills would make a stack almost 7,000 light years high.
2. A mole of mini marshmallows would cover the Earth to a depth of about 1 kilometer.
3. A mole of standard men would weigh about 7 Earth masses.
4. A mole of food calories could feed every person on Earth for about 94 million years.
5. Counting a mole of anything at a rate of one object per second would take about 19 quadrillion years.

#### solution

Avogadro's number is huge! The Avogadro constant in the International System of Units is an astonishing 6.02 × 1023 objects per mole.

1. A mole of dollar bills would make a stack almost 7000 light years high.
2. A mole of mini marshmallows would cover the Earth to a depth of about 1 kilometer.
3. A mole of standard men would weigh about 7 Earth masses.
4. A mole of food calories could feed every person on Earth for about 94 million years.
5. Counting a mole of anything at a rate of one object per second would take about 19 quadrillion years.

### practice problem 2

Write something else.

### practice problem 3

Write something different.