2. The picture shows the moon between Earth and the sun. Why are Earth and the moon not always in this position?
A. because the sun is always moving
B. because the moon travels around the sun
C. because Earth travels around the sun
D. because the tilt of Earth changes

C. Because Earth travels around the sun

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.