During which changes of state does the motion of the atoms decrease?

melting and deposition

freezing and condensation

condensation and evaporation

vaporization and sublimation

Matter exist in three phases: Solid, liquid and gas

The intermolecular forces of attraction is strongest in the solid phase, followed by liquid and then vapor/gas. Greater the intermolecular force of attraction, slower will be the molecular motion. Thus, the atoms will move the slowest in a solid, followed by liquid and fastest in the vapor.

Freezing changes the state from liquid to solid

Melting changes the state from solid to liquid

Vaporization changes the state from liquid to gas

Sublimation changes the state from solid to vapor

Hence, from the given options, molecular motion of the atoms will decrease during freezing and condensation

freezing and condensation

Explanation:

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"

you didnt put any of the following