Re: How many Electron Volts make a Volt, and how many Volts make a Watt?

The answer is the same to both questions, but I'm sure that you'll find it 
unsatisfying:  none.

The reason is that the quantities that you want to compare are actually 
different sorts of things:

Electron volts are units of energy
Volts are units of electrical potential
Watts are units of electrical power

If you use a number of watts for a period of time, the result is that you 
will have used up a certain amount of energy.  In a real sense, you can 
think of watts are electron volts used per unit time...  although watts 
and electron volts are not usually used together.  Usually watts are used 
together with joules -- 1 watt used for 1 second results in a use of 1 
joule of energy; 7.5 watts used for 2 seconds results in a use of 15 
joules of energy.

Similarly, volts can represent the voltage across the output terminals of 
a battery.  If current flows between the terminal through a wire or a 
resistor or another form of circuit, the electrical power used is equal to 
the number of volts times the number of amperes equals the power in watts.

In a very real sense, then, your questions aren't too meaningful.  They're 
like asking how many tires are there in a highway...  Tires are related to 
highways, but the relationship is through another factor -- in this case, 
the number of cars on the highway.

For questions like this, you can always check an introductory physics 
textbook... they have good, long, clear explanations.