How many?

Nanometres

The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American spelling) is a unit of length in the metric system, equal to one billionth (short scale) of a metre (0.000000001 m). To demonstrate just how small a nanometre is, it is commonly used to measure atoms and molecules. A typical virus is around 100 nanometres wide. The coronavirus, known as COVID 19 is believed to be between 60 to 120 nanometres wide.

Metres

The metre, or meter, is the base unit of length in the International System of Units (SI). The SI unit symbol is m. The metre is currently defined as the length of the path travelled by light in a vacuum in 1/299,792,458 of a second. The current world record for running 100 metres is 9.58 seconds, set by Usain Bolt in 2009.