1. Which of these determines whether or not a
material is magnetic?
3. K
A. the density of the material
B. the weight of the material on Earth
C. the alignment of atoms in the material
D. the number of elements that make up
the material

C. The alignment of atoms in the material

Explanation:

Alignment of electrons, atoms, and domains are important in determining the magnetic response of a material and whether it is a magnet. Since the atoms or molecules need to be aligned, gases and liquids are typically not magnetic, and most magnets are solid metals.

i just learnt this recently but i need to look through my notes again