It is too small to be seen.

It reflects light away from Earth.

It does not interact with the electromagnetic force.

It absorbs all light.

It cannot use electrostatic forces to stick together.

It is too dense to form structures.

It cannot generate heat.

It repels other matter.

By forming from tiny pebbles.

By collapsing from a giant cloud like stars.

By absorbing light.

By merging with regular matter.

A way for dark matter to emit light.

A separate variety of electromagnetism for dark matter.

A force that makes dark matter visible.

A method to increase dark matter's mass.

H and L for heavy and light.

Protons and electrons.

Alpha and beta particles.

Neutrons and positrons.