How many significant figures does 0.0002 g

When an object falls through the air and encounters air resistance its overall speed will be than if it had not encountered air resistance? (one word answer)

How much would the freezing point of water decrease if 4 mol of sugar were added to 1 kg of water(k=1.86 c/mol/kg for water and i=1 for sugar

The comparison of the number of atoms in a copper coin the size of a penny with the number of people on earth is made to illustrate which of the following? a. that atoms are indivisible b. that atoms are very small c. that atoms are very large d. that in a copper penny, there is one atom for every person on earth