Nitrogen form Symbol Use in soils and plants; Dinitrogen (Atmospheric Nitrogen) N 2: Dinitrogen is the most common form. It makes up 78 percent of the atmosphere but cannot be used by plants. It is taken into the soil by bacteria, some algae, lightning, and other means. Nitrate: NO 3: Nitrate is the form of nitrogen most used by plants for growth and development.
Reacting when you hear the tornado sirens go off is key. Emergency officials want reaction to be instinctive, not a frenzy of confusion, when you hear the siren sound. You'll have two chances to practice when the sirens sound today. The first drill will happen between 10 and 10:30 a.m. when children are in school.
Siren (alarm) A siren is a loud noise making device. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks. Sirens are used on emergency service vehicles such as ambulances, police cars, and fire trucks. There are two general types: pneumatic and electronic. Many fire sirens serve double duty as tornado or civil defense sirens, alerting an entire community of impending danger. Most fire sirens are either mounted on the roof of a fire station or on a pole next to