Which has more atoms, 6.0 g of silicon (Si:28) or 6.0 of iron (Fe:56)?
Use Avogadro's number as 6.0 x1023

 6.0 g of silicon has more atoms

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number of particles.

To calculate the moles, we use the equation:

a)

1 mole of Si contains = atoms

0.21 moles of Si contains = atoms

b)

1 mole of Fe contains = atoms

0.11 moles of Fe contains = atoms

Thus 6.0 g of silicon has more atoms

8 m/s because for him to get the same amount of energy as ray is putting out, bobby, who weighs half as much as ray, needs to run twice as fast.