What is the mass of a child if the force of gravity on the child's body is 100 n?

Gravity is 9.81m/s^2 on earth F=m×g
100N=(x)kg×9.81m/s^2
x=10.19kg or more than 22lbs

The chemical reactions lab we did is typically called a "copper plating lab,  because the acid solution cleaned the pennies and made the copper look shinier;   the acid solution cleaned the paperclips and made them look like pennies;   &   the copper from the pennies was removed, and then added to the paperclips.