So when they say you take 3 years of Science in Highschool in the US does that mean you take it all year long for 2 straight semesters or you take lets say Freshman year took Science for a semester Sophomore year another semester then Junior year another semester does that count as 3 years or what I'm confused? Cuz I heard 2 different answers

A year of science or any other subject means 2 semesters.

One-semester courses are listed as such.

Are "Chemistry Biology and Physics" all rolled into the same course? Maybe an integrated science course? If so, then you would have taken 2 years (4 semesters) of science courses.

What if I took Science in Freshman year for 2 semesters then Sophomore year I took Chemistry Biology and Physics for another 2 semester what would happen in that situation?

Yes all in the same year for 2 semester Physics Chemistry and Biology

In the United States, the standard requirement for high school science is usually around three years. However, the exact structure and duration of science courses may vary depending on the school or state.

Typically, a science course in high school is taught over the span of one school year, which typically consists of two semesters. Each semester usually lasts for around 18-20 weeks. So, if a student takes a science course for one semester during their freshman year, another semester during their sophomore year, and another semester during their junior year, it would generally fulfill the requirement of three years of science.

It's important to note that different schools may have different approaches to teaching science, so the exact structure and timing may vary. Some schools may offer year-long science courses, where students study a specific science subject for an entire academic year, while other schools may have different arrangements.

To get precise information about your specific high school's science requirements, it would be best to consult your school's academic handbook, talk to your guidance counselor, or check your state's education department website if they have standardized science requirements.