There are two airborne methods of transmission that have been discussed:Depends on the ventilation.
If a place is well ventilated, virus particles will be grounded within 10 seconds.If not they could hang around for a couple of minutes.
Your body needs to breath in quite a bit of small virus particles for it to get established. Far more than from larger droplets. The body is pretty good at filtering it out of the air and in to mucus where it will die or be digested.
From the evidence I've seen between 10% and 30% of coronavirus transmission is via airborne aerosol.
Wrap a scarf around your head before you go shopping. This will stop most aerosol transmission.
- Large droplets, and
- Fine aerosol.
The experience of a church choir where 45 of a 60 strong choir got infected after a choir practise suggested aerosol transmission is a serious risk. https://www.latimes.com/world-nation/story/2020-03-29/coronavirus-choir-outbreak