Answer: There are 
atoms present in 0.500 mol of 
.
Explanation:
According to the mole concept, there are 
atoms present in 1 mole of a substance.
In a molecule of there is only one carbon atom present. Therefore, number of carbon atoms present in 0.500 mol of are as follows.
Thus, we can conclude that there are atoms present in 0.500 mol of .
Answer:
The possible valances can be determined by electron configuration and electron negativity
Good Luck even though this was asked 2 weeks ago
Explanation:
All atoms strive for stability. The optima electron configuration is the electron configuration of the VIII A family or inert gases.
Look at the electron configuration of the nonmetal and how many more electrons the nonmetal needs to achieve the stable electron configuration of the inert gases. Non metals tend to be negative in nature and gain electrons. ( They are oxidizing agents)
For example Florine atomic number 9 needs one more electron to reach a valance number of 8 electrons to equal Neon atomic number 10. Hence Flowrine has a valance of -1
Oxygen atomic number 8 needs two more electrons to reach a valance number of 8 electrons to equal Neon atomic number 10. Hence Oxygen has a valance charge of -2.
Non metals with a low electron negativity will lose electrons when reacting with another non metal that has a higher electron negativity. When the non metal forms an ion it is necessary to look at the electron structure to determine how many electrons the element can lose to gain stability.
For example Chlorine which is normally -1 like Florine when it combines with oxygen can be +1, +3, + 5 or +7. It can lose its one unpaired electron, or combinations of the unpaired electron and sets of the three pairs of electrons.
Mercury expands when it is heated. This process is called thermal expansion.
Answer: 4.15234 m
512 g H2O * 
= 0.512 kg H2O
Nitric Acid: HNO3 = 1.008 + 14.007 + 3(15.999) = 63.012 g/mol
H = 1.008 g/mol
N = 14.007 g/mol
O3 = 3*15.999
134 g HNO₃ * 
= 2.126 mol
m = 
= 4.15234 m
