Which of these scenarios is most likely a chemical reaction?
1. a gas turns into a liquid as it releases energy.
2. a liquid becomes a gas as it absorbs energy.
3. two white solids are added to a colorless liquid, and a colorless liquid remains. 4. two colorless liquids are added together, and a colorless liquid and a green solid remain.

The scenario, which is likely a chemical reaction is this: TWO COLORLESS LIQUIDS ARE ADDED TOGETHER, AND A COLORLESS LIQUID AND A GREEN SOLID REMAIN.

A chemical reaction is said to occur when two or more element combine together chemically so that a new substance is formed as product. Chemical reactions are typically irreversible and the products formed have properties that differ from the properties of the reactants. Looking at the options given above, it is only in option 4 that a new substance is formed, which is a green precipitate. Thus, option 4 showcase a chemical reaction.

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.