b. Polar covalent bonds. The polar N-H bonds hold the NH3 molecules together. They are <em>intramolecular forces</em> of attraction <em>within a molecule</em>.
All the other options are <em>wrong</em>. They are <em>intermolecular forces</em> — the attractive forces <em>between different molecules</em>.
Answer:
Solid, liquid, gas
Explanation:
add thermal energy to solid and it becomes liquid, add thermal energy to liquid it becomes gas
Answer: 12 L fluorine gas at STP can be collected from the decomposition of 90.7 g of 
Explanation:
The balanced decomposition reaction is shown as

moles of 
According to stoichiometry:
2 moles of
gives = 3 moles of flourine gas
Thus 0.36 moles of
gives =
of flourine gas
Using ideal gas equation :

P = pressure of gas = 1 atm ( at STP)
V = Volume of gas = ?
n = moles of gas = 0.54
R = gas constant = 0.0821 L atm/Kmol
T = temperature = 273 K ( at STP)
Putting the values we get :


Thus 12 L fluorine gas at STP can be collected from the decomposition of 90.7 g of 
Use proportions.
1 lightyear = <span>9.4605284 trillion kilometers
</span><span>x light years </span>≈<span> 33.31 </span>trillion kilometers
<span>
33.31/9.46 = x/1
3.50 </span>≈ x<span>
</span>