The coronavirus is not ‘airborne’ like tuberculous, measles, or smallpox for example, which can circulate in the air. However, there may be some evidence to suggest it is airbourne. Transmission of COVID-19 occurs primarily through aerosolized respiratory droplets which can spread the virus and can cause infection in others.
When someone coughs, sneezes, or talks, these droplets can infect another person if they get into their airways. Droplets typically do not travel more than six feet (about two meters) and do not linger in the air. A social distance of 6 feet intends to protect you against infecting another person or becoming infected. Still, the CDC is now recommending the use of face masks in public.
Infected surfaces that have viruses can also lead to infection. And under experimental conditions, the virus can stay alive in air for several hours. Because we don’t know and completely understand this virus, it’s a good idea to take airborne precautions .
Source : http://www.webmd.com