A hydrogen bond is a special form of a(n) a. covalent bond.
b. dipole-dipole force.
C. ionic bond.
d. London dispersion force.

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.