Brock brings a magnet near a metal object. a magnetic force acts on an object, pulling it upward. which of the following best describes the magnetic force? a. a force that acts at a distance b. a gravitational foce c. a frictional force d. a contact force

A. a force that acts at a distance

Explanation:

Magnetism is a force that acts at a distance so it is possible to attract a metal object through a magnet that is at a certain distance.

Magnetism is a set of phenomena related to the interaction between magnetic fields, which are the regions of space that are under the influence of electric currents or the magnetic moments of elementary molecules or particles.

The movement of electric charges is what gives rise to magnetic phenomena. Since they are never standing still, atoms produce their own magnetic field. In addition, elementary particles such as protons, neutrons and electrons also have an intrinsic magnetic field, but of a different origin. The magnetic field of these particles comes from a quantum property called spin.

pure substance: iron,copper

impure substance: water,charcoal

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.