I need help! i don’t really understand this

the answer is na (sodium)

fe 55.85 g/mol and h2o 18.02 g/mol.

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 : )