Answer:
There are five signs of a chemical change:
Color Change.
Production of an odor.
Change of Temperature.
Evolution of a gas (formation of bubbles)
Precipitate (formation of a solid)
Explanation:
I just went ahead and gave you the five signs of chemical change hoped it helped
Weight=100N
SF=0.4
KF=0.3
Magnitude?
0.4 x 0.3 = 0.12
0.12x100=12
Ans =20