Question

the three substances that form natural magnets are ______.
a. iron, nickel, and cobalt
b. iron, boron, and cobalt
c. copper, nickel, and boron
d. copper, iron, and cobalt

Explanation:

Identify the core question

The question asks for the three substances that form natural magnets.

Analyze the options

Using the Ferromagnetism knowledge point

• Iron, nickel, and cobalt are the three primary naturally occurring ferromagnetic elements.
• These elements have unpaired d-shell electrons that align to form strong magnetic fields.
• Other options contain elements like boron (metalloid) or copper (diamagnetic), which do not form natural magnets.

Select the correct option

The correct combination is iron, nickel, and cobalt, which corresponds to option a.

Answer:

• a. iron, nickel, and cobalt (Correct answer)
• b. iron, boron, and cobalt
• c. copper, nickel, and boron
• d. copper, iron, and cobalt