Which of the following requires a chemical change? A. Melting chocolate on a graham cracker
B. Toasting a marshmallow over a fire
C. Letting the fizz escape from a soda
D. Blending mustard and ketchup on a bun

C

Explanation:

When you let the fizz out of soda you are making it no longer sodo so a b and d are not correct

a. they are both space stations

happy to

pls mark as brainliest.

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.