During a science experiment, your teacher does a demonstration. She takes a small piece of rope, weighs it to find its starting weight, burns it, and then
weighs it again. The final mass of the product is different from the starting
weight of the reactant.
Why is the final mass different? Does this mean that the product has less
mass? Why or why not?

less mass

Step-by-step explanation:

The product has less mass because some of its mass got burned. Hope this helps!

some parts of the rope turned into gasses because of the intense heat (fire)

costs the what? what is the cost of the pants?

step-by-step explanation:

if it is $10, then the price is 14.

take 40% of the cost, and then add the cost.

40% of 10 = 4

4+10 = 14.