Question

which ems wave has the longest wavelength (building - sized) and is used for communication? microwaves radio waves visible infrared

Explanation:

Step1: Understand the electromagnetic spectrum

The electromagnetic spectrum (EMS) is a range of all types of electromagnetic radiation. The order from longest to shortest wavelength is: radio waves, microwaves, infrared, visible light, ultraviolet, X - rays, and gamma rays.

Step2: Analyze the uses

Radio waves have very long wavelengths (can be building - sized or even longer). They are widely used for communication purposes such as in radio and television broadcasting, mobile phone communications, and satellite communications. Microwaves have shorter wavelengths than radio waves and are used for cooking (microwave ovens) and some communication (e.g., satellite communication in a different band compared to the main radio - wave - based communication). Visible light has much shorter wavelengths and is used for vision (by humans and other animals) and some optical communication (but not in the "building - sized wavelength" context). Infrared has wavelengths shorter than microwaves and is used for remote controls, thermal imaging, etc.

Answer:

Radio Waves