What causes nickel and certain other metals to be magnetic?
a.
the motion of protons in their atoms
b.
the pattern of electrons in their atoms
c.
their atoms have more electrons than protons
d.
the influence of the earth's magnetic field
where is the magnetic field of a bar magnet the strongest? a. at the north and south poles b. between the north and south poles c. in the middle of the magnet d. next to the south pole

The pattern of electrons in their atoms causes nickel and certain other metals to be magnetic. The correct option is B. The bound electron in elements occur in pairs. Some element have unpair bound electrons which set up tiny magnet effects inside the atoms. When such unpaired electrons are plenty in an atom, they cause the element to be magnetic in nature. For the second question, the correct option is A. Bar magnetic magnetic fields are strongest at both poles, that is, at the south and the north poles.