Answer:
1, their atoms have the same number of valence electron. because valence electron determine the group of elements.
To solve this exercise it is necessary to apply the equations related to the magnetic moment, that is, the amount of force that an image can exert on the electric currents and the torque that a magnetic field exerts on them.
The diple moment associated with an iron bar is given by,

Where,
Dipole momento associated with an Atom
N = Number of atoms
y previously given in the problem and its value is 2.8*10^{-23}J/T


The number of the atoms N, can be calculated as,

Where
Density
Molar Mass
A = Area
L = Length
Avogadro number


Then applying the equation about the dipole moment associated with an iron bar we have,



PART B) With the dipole moment we can now calculate the Torque in the system, which is



<em>Note: The angle generated is perpendicular, so it takes 90 ° for the calculation made.</em>
Answer:
C. Car A
Explanation:
if the answer is: which roller coaster car has the greatest potential energy due to gravity brainly
When a swimmer pushes through water to swim they are propelled forward because of the water resistance against the hand and feet. It's A. The water doesn't automatically push the swimmer forward. It releases a reaction after the swimmer pushes through the water.