Ow is an electromagnet different from a bar magnet?

question 3 options:

a. only a bar magnet has a magnetic field.

b. only an electromagnet attracts materials made of iron.

c. an electromagnet is temporary and is magnetic when a current flows through a wire wrapped around the core.

d. a bar magnet is a temporary and is only magnetic when a current flows through a wire wrapped around the core.

In positive numbers less than 1, the zeros between the decimal point and a non-zero number are blank significant

Which of the following compounds would be primarily ionic? methane, ch4, ammonia nh3, calcium chloride, cacl2, or carbon dioxide, co2

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?