Suspended particles seem to float in liquid. You may have seen hand sanitizing gels with tiny suspended dots throughout the clear liquid.
Particles that are suspended seem to hang in a liquid. In fact, Old French and Latin define pendere as "hang." Think of other words you know that are like suspended, such as that word's other definition, "to put off temporarily." A student suspended from school has not been kicked out, but instead is left hanging between periods of enrollment. Then there is pending: a decision that is pending hasn't been made yet, so people wait, hanging on until they know what will happen.