it's the last one because it's depended on the rock layers
74 is the answer u find it by subtracting the protons(atomic number) from atomic mas, so basically... 127-53 =74 neutrons
Answer:
0.025536g
Explanation:
no. of mole = mass/Mr
mass = Mr × no. of mole
= [23 + 1 + 12 + 3(16)] × 3.04×10^-4
= 0.025536g
= 0.0255g (3 significant figures)
1.5*9.8*1.2
since the formula is force * distance.
1.2 is the distance. the force is gravity on the object (1.5*9.8)
The answer is 17.64 J . (18 J with sig figs)
