4. To keep cool in the summer months, you decide to design and build your own hand-held fan. The fan's electrical circuit will run off of 4 AA batteries (each with a voltage of 1.5 V) and must not exceed 50 mA of
current. You visit your local Radio Shack and find that resistors are sold in five varieties: 5 Ohm, 10 Ohm, 12
Ohm, 20 Ohm, 50 Ohm. Each resistor costs 8 cents. What set of resistors should you buy to minimize cost?

Calculate the minimum energy required to remove one proton from the nucleus 126c. this is called the proton-removal energy. (hint: find the difference between the mass of a 126c nucleus and the mass of a proton plus the mass of the nucleus formed when a proton is removed from 126c.) express your answer with the appropriate units. emin e m i n = nothing nothing request answer part b how does the proton-removal energy for 126c compare to the binding energy per nucleon for 126c, calculated using eb=(zmh+nmn−azm)c2?

If the pressure in a gas is doubled while its volume is held constant. true or false

Atoms seldom exist as independent particles in nature a) as single particles, most atoms have low potential energy b) their electronegativity is much lower when they combine with other atoms c) atoms are more stable when they combine with other atoms d) neutral particles are rare