What subatomic particle has negligible mass and travels around outside the nucleus?

a. a primary source combines several different accounts of an event. b. a primary source generally benefits from having been written after an event.

explanation:

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary