In oaxaca city, mexico, noche de rábanos is celebrated every 23rd december. which food gives this festival its name?

Spanish term - Noche de rabanos, translated in English reads as Night of Radishes.

The Night of Radishes is an annual celebration in Oaxaca, Mexico where competitors carve oversize radishes to creates scenes and win prizes in various categories.

This event originated in the colonial period where farmers carve on the radishes to attract customers to their stalls and buy from them. The farmers' stalls are grouped together in the main square to form a Christmas market on every 23rd of  December.

This practice of radish carving was made official in 1897 where it became an annual competition.

1*10^9 molecules* (1 mol/ (6.02*10^23 molecules))= 2*10^(-15) mol.

The final answer is 2*10^(-15) mol O2~