Phenomena Forum
Being a biology teacher, my first idea of phenomena for two objects interacting through electric/magnetic fields is two or more molecules or water that form Hydrogen bonds (from the negative oxygen of one molecule to the slightly positive hydrogen of a near by water molecule).
For the middle school standards, I would build a phenomena around how both your heart rate and breathing increase when you exercise.
I teach middle school science and love to use phenomena based experiences. One of my favorites is some chemical reactions produce heat while other chemical reactions take in heat. An assessment that I have paired with this phenomena is to have students design reptile egg incubators that capitalize on a chemical reaction. The assessment was inspired from resources provided by https://www.middleschoolchemistry.com/
Concerning the heating and cooling of matter, a phenomena that could be explored is how temperature effects the race time in the Iditarod Race.
You could compare structure and function of cells with the following phenomenon: White blood cells have a nucleus and red blood cells do not have a nucleus.
You could stress the organization within of cells, tissues, organs, and organ systems with the phenomenon: The digestive and respiratory systems work together to power our bodies.
Hello!
I think a great phenomena is exploration of gravity as a weak force when compared to electrostatic ones (phenomena), such as when your hair stands up when you brush it during the winter (context)

Energy is stored in magnetic fields.
A phenomena that we do in my class is a plant in a jar to demonstrate the connections between photosynthesis and cellular respiration
We have sunflowers bordering the side of our playground which lends itself to the phenomena of the young flowers following the sun. It kicks off great discussions around the structure and function of plants in our high desert environment.
The phenomina that I use to show 5th grade students that matter is made of particles that are too small to be seen is to deflate a balloon onto a pinwheel to cause the pinwheel to turn. This will suggest that there are particles of matter leaving the balloon too small to be seen.
Looking at the middle school standard around cells and organelles and building a model to explain their interactions I would examine the relationship of parts of a whole of a city or pocket watch where each part contributes to the well being, functioning and survival of the whole.
I was also thinking about the Sunflowers and according to researchers only young sunflowers follow the sun and adult sunflowers face east.