I taught HS Chem for 20+ years. Juniors can handle on-level Chemistry but Sophomores not so much. It's a matter of concrete thinking as well as maturity.

I retired last May but earlier this school year I did a long-term sub job at a school in my district. At this school sophomores took on-level Chem while at the school I retired from taught juniors. The juniors were much better able to grasp the abstraction. Maturity was a real issue with the sophomores - fart noises during exams, kicking tables, knocking papers on the floor, leaving a mess behind. I was never so glad to have a job finish - and won't do another long-term sub job. I'm supposed to be retired!

I still sub a couple days a week but that's my limit - unless it's for a teacher in my old department. It's great to be back "home" for a little while but not every day.

Chem not taught in freshman year @ my high school (last year @ the Jr. High school,) do remember not liking chem teacher, creepy guy. Too bad.

Don't recall high school Bio, but did well in freshman college bio class (tho huge class.)

They just coincidentally changed what I expressed was an issue, 5 years after I brought it up.
My PhD is in physical organic chemistry so I kind of know the thought processes & the learning sequence that makes sense.
As another reply stated from experience, and from my HS days, chem should be a junior level course.
At least sophomore year is better than the first year.
Biology is likely better, because it helps kids organize concepts & learn the "what" before they take disciplines involving abstraction and "how" things work.
At a few other HS, freshman take Earth Science, which is kind of general science with a little more depth than what they had in junior high. Then, bio, chem & physics in that order.
That makes more sense to me. I might even put physics ahead of chem.

My kid is doing chem in 10th grade. I did Advanced Bio in 9th, Adv Physics in 10th, Chem in 11th and Adv Chem in 12th. I was out of place doing Physics b4 chem, but I wasn't the average student. Just keep at it and look for supporting information to what you suggest is better for student success.

I've got no clout. I am subject matter expert, but not an educator.
I just have a personal interest because I see these kids in math & science classes 60 or 70 times a year.
It's just a useful hobby.
I live near Chicago so golf is not a 365 day a year avocation.