Why is coal costly to produce?
1.coal is found deep underground.
2. coal is expensive to make
3. coal is only found in certain places on earth.
4. coal is difficult to make in the lab.

Phase changes are chemical changes. true or false

How does a circuit breaker protect a refrigerator? a. when the current is too high, a metal strip in the fuse melts and opens the circuit. b. when the resistance is too high , a re-settable which opens a circuit c. when the current is too high , a re-settable switch opens the circuit d. when the resistance is too high a metal strip in the fuse melts and opens the circuit

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?