Many smoke detectors use a isotope of americium to detect the smoke. when a stream of alpha particles is emitted from the americium nucleus it can be blocked by small particles of smoke. this is then detected and sends off an alarm.

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.

well first you need the sample of the temperature and gas level. i couldnt write a hypothesis unless i had some data. i think temperature changes will effect volumes of gas because gas changed into a solid or liquid at specific temperatures.