Ask Singapore Homework?
Upload a photo of a Singapore homework and someone will email you the solution for free.
Question
primary 5 | Science
One Answer Below
Anyone can contribute an answer, even non-tutors.
Why is the answer 4?
fact : most, but not all, gases are invisible.
common gases like oxygen, carbon dioxide, nitrogen, etc, are all invisible, but there are some substances like chlorine & bromine that are visible in their gaseous state. these are not within primary school science syllabus. but are covered in secondary school science.
See 1 Answer