A mole is a unit of many particles (atoms, molecules, ions) where 1 mole is the number of particles contained in a substance that is the same amount as many atoms in 12 gr C-12

1 mole = 6.02.10²³ particles

mass of N in 0.82 g of NaNO₃ (MW NaNO₃: 85 g/mol) :

$\tt mass~N=\dfrac{Ar~N}{MW~NaNO_3}\times mass~NaNO_3\\\\mass~N=\dfrac{14}{85}\times 0.82\\\\mass~N=0.135~g$

moles of N :

$\tt mol=\dfrac{mass}{Ar}\\\\mol=\dfrac{0.135}{14}=0.0096$

The number of atoms N :

$\tt N=n\times No\\\\N=0.0096\times 6.02\times 10^{23}\\\\N=5.8\times 10^{21}~atoms$

4 0

3 years ago

Is PH3 polar or nonpolar

Andru [333]

Answer:

polar

Explanation:

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What happens when an object heats up? what happens when an object cools down?

Nataly_w [17]

Answer:

Heat will flow from the hotter object to the colder. The molecules in the hotter object will slow down and the molecules in the colder object will speed up. Eventually they will get to the point where they have the same temperature. This happens all the time around you.

Explanation:

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3 years ago

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