Plz help asap Choose all the answers that apply.

The elements in group 18 .

are highly reactive
are gases at room temperature
usually do not react with other elements
are in a group called the noble gases
are nonmetals

As a part of an experiment a student burns propane to produce carbon dioxide and water she remembers that she must follow the law conservation of matter when writing a balanced chemical equation which of these equation adheres to the law of conservation of matter

Which of these conditions most likely produces an unstable isotope?

What is the percentage composition of carbon in the compound ch4