Which factor is most important to keep the same when comparing the hardness of solids? A. The temperature of the hot plate
B. The amount of each substance
C. The intensity of the light
D. The method of making a scratch on the material​

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )