25 POINTS!

Which of the following is the first law of thermodynamics?

A. The entropy of an isolated system will always increase.

B. Energy can not be created nor destroyed.

C. The entropy of a system approaches a constant value as the temperature approaches absolute zero.

D. The entropy of an isolated system will always decrease

The Answer is B. Energy can not be created nor destroyed.

Explanation:

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.