Why do helium balloons pop in a hot car?

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

Drug abuse will not lead to physical and psychological dependence. true or false ?

The missing component to the table to the right or indicated with orange letters complete the table by filling in the corresponding numbers or symbols