1st Generation Pesticides: 1  2500 BC- farmers began using the toxic chemical sulfur to kill off pests from their crops. 2  15th century AD -a variety of chemicals such as, arsenic, hydrogen cyanide, mercury and lead were put to use. 17th century -nicotine sulfate, derived from tobacco leaves was discovered as an effective pesticide and ants were controlled with mixtures of honey and arsenic.
Cell phones communicate with nearby cell towers mainly through radiofrequency (RF) waves, a form of energy in the electromagnetic spectrum between FM radio waves and microwaves. Like FM radio waves, microwaves, visible light, and heat, they are forms of non-ionizing radiation.
cell phone or cellÂ·phone (sÄlâ²fÅnâ²) n. A portable telephone that sends and receives radio signals through a network of short-range transmitters located in overlapping cells throughout a region, with a central station making connections to regular telephone lines. Also called cellular telephone, mobile phone. cellphone (ËsÉlËfÉÊn) or cell phone. n (Telecommunications) a portable telephone operated by cellular radio. In full: cellular phone or cellular telephone. Thesaurus Antonyms Related Words Synonyms Legend: Switch to new thesaurus . Noun: 1. cellphone - a hand-held mobile radiotelephone for use in an area divided into small sections, each with its own short-range transmitter/receiver. cellular phone, cellular telephone, mobile phone, cell