4) in a chemical change a substance forms.

it should have an internal chamber and two thermometers sticking out of the top. the internal chamber will also be closed off from the outside.

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.