When ethanol is burned, it's converted into carbon dioxide and water. does the ethanol undergo a physical change or a chemical change? explain?

It's a chemical change because ethanol is converted into other substances.

B.1 - hydrogren-1 can only mean there is 1 neutron. it's obvious there is 1 proton or else it wouldn't be hydrogen, so they wouldn't put a number after it unless they were indicating the number of neutrons

Polyethylene is a strong synthetic polymer that can be used to make toys and bottles. this makes plastics which are important also to people but sometimes it lead to harmful environmental effects such as global warming if these plastics are burned.