From Disney Theme Parks, the narration for the now-defunct Adventures Through Inner Space did this several times.
(while the car is surrounded by giant snowflakes) "These are snowflakes!"
"And yet this wall of ice only seems smooth and solid. From this tiny perspective, I can see that nothing is solid, no matter how it appears!"
"Yes... these are water molecules! H2O... Two hydrogen atoms bonded to a single oxygen atom."