This is a particle (virion) of corona virus SARS-CoV-2, determined by electron microsopy.
The particle is composed of three parts: spike proteins, lipid membrane envelope, and RNP (ribonucleoproteins).
The spike proteins play very important roles for the viral entry.
The RNPs are composed of N proteins and a single RNA chain, which stored genomic information of the virus.
The diameter of this particle is about 20 nm. Note that the diameter of a human cell is about 200 times larger than that of the virus particle.
RNP(RNA and N proteins)