Not sure on a reasonable estimate for the weight of a pencil. Out of the choices given I have it narrowed down to 1x10^-2 lbs or 1 x 10^-20 lbs. I know it is not the other 2 choices because they are positive exponents and would be too heavy. Thanks.

Answer 1

1x10^-2 = 1/100 lbs = 4/25 oz
seems a bit light, but it's a lot closer than
10^-20 = 1/100000000000000000000 lbs!!!