Pb(NO3)2
how do i solve this

You can see the periodic table one by one.

Pb(NO3)2 = PbN2O6

So there are

1Pb

2N

6O

and so you find the molecular mass from the periodic table and add all the numbers

Molacular mass of

Pb = 207

N = 14

O = 16

multiply it with the number of atoms

1Pb = 207 × 1 = 207

2N = 14 × 2 = 28

6O = 16 × 6 = 96

Molecular mass total = 207 + 28 + 96 = 331

So the molecular mass is 331.

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 : )