measured quantity must be expressed with the proper number of significant figure to indicate its precision?

Aperfume bottle is dropped in the corner of a room. the odor of the perfume can be detected on the other side of the room. which statement best describes this observation?

Nuclear decay is the spontaneous decay of one element into a. an x-ray b. a ray of light c. another element

Atoms contain subatomic particles called protons and neutrons. when these protons and neutrons spilt, a lot of energy is released