I think you have misunderstood our messages a bit. Your quiz was science-themed but not truly "about science". In the end, the categorization of a quiz depends on the knowledge you need to answer the questions.
Here are two questions, inspired by one that you wrote:
Q1: Forensic science is a fascinating field and applies knowledge from physics, biology and chemistry to solving crimes. Set in Florida and starring David Caruso, which television series has done great things for popularizing this field?
Q2: In "Star Trek: The Next Generation"'s second season, Doctor Pulaski used a stasis field to conserve tissues for later examination. More conventionally, she could also have used a liquid with the formula CH2O - what is its name?
Superficially, Q1 looks like a science question and Q2 like a television one, but in reality it is the exact other way around. Here are the questions again, stripped down to their essence (the information that you actually get for answering them):
Q1a: Which of the following TV series is set in Florida, concentrates on forensic science and starred David Caruso?
Q2a: Which liquid, used to preserve tissues in biology, has the chemical formula CH2O?
Q1a is clearly a television question. Q1 is the very same question, but with additional text that themes
it as science. You are putting the TV question into a science "story". It could be part of a quiz called "A scientist's television lineup" where you explore the portrayal of various sciences on TV.
Q2a is a science question, Q2 is the same question themed towards "Star Trek". It could be part of a Sci/Tech quiz that looks at real-life equivalents for some sci-fi solutions that "Star Trek" characters have used.Bottom line
: FunTrivia questions are classified by their core - what is the knowledge actually being tested - not by their outward theme.
If you want to make sure your questions fall in the right category, you can use a bottom up approach. First think of a plain fact in the field you want to write about, then wrap that fact in your desired theme. Let's say you want to do something on chemical compounds and formulas, so we will want to have a chemical formula and the material as the core of each question.
You come up with the fact that SiO2 is the main component of glass. Now you want to put that into the "Gifts from your mother" context that you tried to use for your quiz.
"For my last birthday, my mother gave me the four gifts listed below. One of them was extremely carefully wrapped because, mostly made of the compound SiO2, it was quite fragile. Which one was it?"
Answers: A glass figurine (correct), a brass ornament, a nacre mobile, a wooden carving
I hope this explains it!