Answer:
16.06 L was the initial volume of the balloon.
Explanation:
Initial moles of freon in ballon = 
Initial volume of freon gas in ballon = 
Moles of freon gas added in the balloon = n = 3.50 mole
Final moles of freon in ballon = 
Final volume of freon gas in ballon = 
Using Avogadro's law:
( at constant pressure and temperature)
16.06 L was the initial volume of the balloon.
Answer: There are 0.000043 moles of melatonin.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
given mass = 10 mg = 0.01 g
molar mass of 
= 232.28 g
Thus there are 0.000043 moles of melatonin
Answer:
a) 2
b) 2
c) 5
d) 5
e) 5
Explanation:
a) There is 1 Ag atom and 1 Cl atom. <em>When there's no subscript number next to an element, it means there is only one.</em>
b) There is 1 Ca atom and 1 O atom.
c) There are 3 Mg atoms (there's a subscript 3 next to Mg) and 2 N atoms.
d) There are 2 Al atoms and 3 O atoms.
e) There are 2 Sc atoms and 3 S atoms.
The answer is Ra
Atomic number for Be is 4
Atomic number for Mg 12
Atomic number for Ra 88
Atomic number for Ba 56
Because you are never adding more than the substances created, nor are you creating any, but should a chemical reaction take place you could see the liquid change form into a gaseous state and that would result a loss of the liquid volume.
So to wrap it all up you can’t have more liquids than what is already there but you could always lose some due to a chemical change, hence the reason it says an open flask, the chemical change would not be collected, mass would be lost
